There are many style manuals available at Burling. Each professor should check to make sure the preferred one is on reserve and then demonstrate its use to the class. Many professors insist that notes taken in class be cited if their content appears in written work. When this is the case, and if the technique for such citation is not covered in the manual, the professor should show how it is to be done. Professors should anticipate these problems so as to avoid having to bring a charge of plagiarism against an otherwise innocent student.
Students sometimes lose sight of the source in the notes they take while doing research.
Much is garbled in an idea's journey from library to word processor to paper, and this is probably one place where the professor can do little more than warn the class that the natural tendency to human error will be no excuse if verbatim quotations are not treated as such, or if paraphrases written in the library, in the student's own words, over time take on the quality of the student's own thoughts and fail to be properly cited. Lapses like these are the students' responsibility, but like all such responsibilities, they won't be honored unless the professor is firm.