You cannot cram an entire quarter or semester's worth of information into one or two nights of studying. Get started on Monday the week before final exams. Think of finals week as finals weeks. College finals are designed to make you think. There are also comprehensive finals.
Comprehensive finals cover all of the information covered from day one of the class.
Determining which type of final you will be taking could make a huge difference in the time you'll need to commit to studying for a particular final. If you are 23 chapters behind in your reading for a class, don't spend the night before the final trying to read the material for the first time. As tempted as you are to study with your friends, best bet is to find a place of your own where you can think. Avoid the mass hysteria at the student union and flee from people wanting to borrow your notes. An Old Test Don't spend the entire night before trying to run down a copy of last year's exam.