Beginning law students often ask what hornbooks or supplements they should read in addition to their casebook for each 1L class.  There are four main types of reading supplements or study aids which may help you interpret the cases you study in class and prepare for exams: 1) Hornbooks or student editions of practitioner treatises; 2) Short treatises or summaries; 3) Primary sources such as model codes or restatements; and 4) Question and answer study guides.  Some people use other supplements such as outlines or collections of case briefs keyed to specific casebooks.  But this guide covers mainly the longer and more detailed types of supplements. 

While commentaries and study guides can be a great help, you should use them only to the extent that they actually do help you understand the law and the cases you study in more depth or with less wasted effort.  Don't make the mistake of trying to read so much that you get behind in reading cases, lose sight of your professor's focus, and overload yourself with more material than you can comprehend.  You should plan on reading no more than one treatise for each class and one shorter question and answer type guide if you find it useful. 

Most treatises are around 800 - 1,200 pages, and most casebooks are around 1,000.  With three classes per semester, you can probably cover a casebook and treatise in each class with about 20 - 30 hours of reading per week.  That assumes that you can read about 20 pages per hour, and should leave you 15 hours a week for reviewing, outlining, legal writing assignments, and practice exams.  If you spend another 15 hours a week in class, then that will mean about 60 hours a week total -- a heavy workload, but not crushing as long as you manage your time well.  You'll probably spend more time each week reading around the start of the semester, and more time reviewing and taking practice exams around the end. 

Whatever commentaries or other study aids you plan to use, just make sure that the total number of pages you expect to read is within reason -- no more than 5,000 to 8,000 pages at the most depending on how fast you find that you can read and understand.  A gross excess in reading material will only distract from other important tasks like reviewing and outlining or will just wind up being wasted because you never get around to reading it. 

Hornbooks

Your main supplemental reading should be a hornbook or major treatise.  These cover the concepts which you're expected to learn from the cases in detail, and they explain the policies or reasoning which underlie what often seem like bizarre holdings in the cases you will read. 

A good treatise will lay out the major competing views on what the rule should be in a given situation or different ways in which judges may interpret a given rule.  They will also usually explain the history of each rule and how or why it came to replace whatever rule came before.  This background will help you move much faster through your casebook reading, home in quickly on the holding in each case, avoid wasting your time on useless prattle or dicta, and spend more time thinking about why a judge chose to decide a case one way rather than another. 

Some people use the term hornbook loosely to refer to any narrative style commentary on the law.  I use it here to refer only to single volume commentaries on the law based on abridged or student versions of longer practitioner treatises.  Each field of law such as torts has one or two major treatises which you will find that judges, scholars, and lawyers rely on.  Appellate courts often cite these works in their opinions to support their reasoning, and lawyers may cite them as persuasive authority in making their arguments.  These books will not only help you learn the law for law school, but will also help you understand the law in practice. 

In the classic picture of a lawyer's office with those long book shelves around every wall, most of the books you see are the full length practitioner editions of these treatises.  Most of those many volumes are called "digests," which are updated each year and contain exhaustive lists of every published case in any jurisdiction which has ever cited that treatise.  Student versions of these treatises leave off the dozens of digest volumes and just include the first one or two that contain the commentary on and summary of the law.  The authors may also abridge comments that they don't think will help most students, in order to fit multi-volume commentaries into a single cover. 

Treatises will often cite or explain cases featured in your casebook, but they are not tied to casebooks in the sense that you will sometimes see commercial outlines "keyed" to a particular author and edition.  Treatises are arranged around logical topics in the law rather than analysis of single cases.  In order to find coverage of a given case from your casebook, you can use the table of cases in the back of the treatise to see in what sections it is covered.  Keyed outlines or case briefs, on the other hand, cover the same cases in the same order as presented in a certain casebook.  But even though treatises are not keyed in this way, you will sometimes find that they offer a much more valuable "key" to your cases in that they are written by either: 1) The author of the casebook you're assigned; 2) The professor teaching your class; or 3) If you're very lucky, both 1) and 2). 

Treatises tend to be long (1,000 - 1,300 pages) and expensive (around $60 each).  So they present a big investment both in study time and money.  If you can, you should always prefer one written by 1) Your professor; or 2) The author(s) of your casebook.  You won't know which professors and casebooks you will be assigned until a few weeks before your first day of class.  So you should probably wait until then to decide which, if any of the major treatises you want to buy.  Also, your law school library will have all of them, so you may find that you can do all your reading from them without needing to buy any.  Keep in mind that most casebooks and treatises have multiple authors, so you should check out all of the names to find possible overlap. 

In the event that you don't have a professor or casebook author who has written a treatise in a subject, and if your professor doesn't suggest one, then you might as well choose the one which is regarded as the "classic" or "bible" in that area.  For some subjects there is one hallowed classic, such as Prosser & Keeton in torts.  For others like property (which spans everything from Landlord - Tenant relations to Trusts & Estates), you will have a hard time finding a single reliable volume that covers the whole ground.  In the absence of any better standard you can look at citation counts to get a rough sense of which authors get the most respect from courts and scholars. 

Fred Shapiro published an article listing "The Most-Cited Legal Books Published since 1978," which makes a good starting point when seeking out the classics.  29 J. Legal Stud.  397 (2000).  Shapiro's list of the Top 20 most cited treatises doesn't feature titles in every subject, partly because it only lists citations by scholars.  Some subjects just don't attract that much attention from scholars, or modern writers may only be working in certain narrow subsets of them.  So I also used Westlaw to get rough citation counts for some common treatises. 

From Shapiro's list, here are treatises that appear in the Top 20 and that cover the common 1L subjects:

Note that Wright and Moore have never produced student editions, so these only exist in the full length versions targeted to practicing lawyers.  You can find the current versions of both in your library, but keep in mind that they'll be far more detailed and comprehensive than the survey or student editions produced for some other subjects.  So if you use these at all, you should be careful to study just those parts that apply to your professor's emphasis for your class. 

Below are Westlaw citation counts for the most popular treatises in both Journals (JLR) and published appellate court opinions (ALLCASES).  The first number is total citations, and the second includes only those from the last three years (JLR) or last ten years (ALLCASES).  In most areas one author clearly dominates, although some subjects have two authors with heavy influence.  Westlaw won't return more than 10,000 results from searches, so those works with citation counts of 10,000 most likely have more actual cites.  Keep the following notes in mind while looking at the raw citation counts. 

Civil Procedure: Wright and Moore clearly rule, as hinted at by their positions on the Top 20 list.  Friedenthal offers the only one volume work on the subject, but scholars and judges alike seem to ignore it with great enthusiasm. 

Contracts: Corbin's treatise has a huge number of case citations, mainly because it's been around far longer than some of the others.  But it was last updated in 1952, and Farnsworth has taken over, especially among scholars, in recent years.  White's treatise has great influence but covers only the UCC, so you will need something else as well if your professor spends a lot of time on the common law (Restatement 2d).  Calamari & Perillo, though popular with students, seem to get little attention from either judges or scholars. 

Property: Again because of the huge scope of the subject, there seem to be few well regarded comprehensive, single volume treatises.  Powell is, like Wright and Moore, the bible for practicing lawyers but does not exist in an abridged version.  Powell also covers only real property, so you will need to look elsewhere for some of the subjects like personal property that the usual 1L class will cover.  Stoebuck offers a single volume treatise, but also covers only real property and seems to have little influence among scholars and judges compared to Powell. 

Torts: Prosser & Keeton have had an overwhelming historical influence, but their grand work was last updated in 1984.  It's worth noting that Dobbs only published the first edition of his treatise in 2000, and he was a co-author on Prosser's final edition.  Dobbs has much better coverage of recent law in areas like product liability, which has changed a good bit in the last twenty years.  He obviously intends his volume to carry on the tradition of Prosser, but his work has not been around long enough for its influence to show up in citation counts. 

Constitutional Law: Tribe has had a huge impact, but Nowak & Rotunda still get a fair amount of attention and offer more recent coverage with their last edition released in 2004.  Tribe also never released (and now says he never will release) the second volume of his work.  But his first volume still covers most subjects that you will see in an introductory Con.  Law class. 

If you want to read something as an introduction to each subject during the summer before law school, or if you just want something comprehensive but shorter than a major treatise, then you might consider:

Epstein and Dressler also edit popular casebooks in these subjects.  Some of these -- especially the Understanding series -- are thorough enough to stand on their own as short treatises.  Sprankling might be all you need for Property, and covers the entire ground better than some much longer works.  If you are using casebooks by Dressler or Epstein, then these short treatises might be all you need to make the most of them. 

I don't see much merit in the popular outline format supplements, but there are a few which were written by prominent teachers or casebook authors that you might look at if you happen to draw their casebooks:

And because future interests give many people problems in property, some also recommend Wendel (Possessory Estates & Future Interests Primer) as a short supplement just for this topic. 

Primary Sources

You will also want to find a primary source for the law in each of your subjects.  Unless your professor teaches to the laws of a particular state, this will be something like a model code, the federal rules of civil procedure, or a restatement, depending on what focus your professor takes.  This will allow you to get a real overview of the law in the books in each area, and will help you to tie together the sometimes scattered treatments and citations in your casebook and supplements.  The structure of a code or restatement will also make a good starting point in organizing your notes and creating an attack outline for exams. 

Not all of these are equally useful.  The restatements on torts and contracts, for example, have had a huge effect on the development of law and theory in these fields.  But the restatements for property have been less successful, and may or may not line up well with the views of your casebook author or teacher.  None of these are literally The Law in any real jurisdiction.  But all states have enacted some form of the UCC, and many have enacted criminal codes based substantially on the MPC. 

If your class doesn't have an assigned statutory supplement for this purpose, then these are some common cheap and decent editions which may work:

If you think that a study guide in multiple-choice or Q&A format might help as you review concepts, then you may consider some of those below.  These won't give you comprehensive overviews or explain topics in detail, but they may help consolidate your understanding once you've read the commentaries and cases:

Don't forget that you'll also be taking Legal Writing both semesters of 1L, and most people need as much help with this as with any area of substantive law.  If you read nothing else on writing before law school, then at least get through Garner's Elements of Legal Style, which should take less than a day.  And if you have any designs on making law review, then you should read the section about write-on competitions in Volokh's Academic Legal Writing any time before your spring classes start. 

Finally, if you only want to read one book before law school but still want to learn something that you may actually use, then try Levi's Introduction to Legal Reasoning.  It will give you a good start on learning to read a line of cases, and it will probably be the last book this small that you will read for a long time.