What many people don't realize is that one storebought book is not enough to sufficiently prepare for the LSAT. Often students start off with purchasing one book and then work through that book and expect scores in the 170 range.
I remember, I bought the LSAT in 30 Days Book
and then I was wondering why I was just not getting any better...duh!
What full length classes do is to provide you with materials and a study sequence. The course consists of explanations and of real LSAT questions and practice tests.
Mind you classes cost over $1,000 and you could do it in form of self study for about $200 or less, in terms of getting the materials.
If you feel that you really do not have the discipline or the ability to do a self study program, then take a class. Also, with a class you do get the opportunity to have somebody verbally explain the strategies versus just reading about them. If you are an auditory learner, then a class may help. However, you can accomplish the same thing with a study group.
If you are inclined to do your own prep, then the following books are a must:
1) Powerscore Logic Reasoning Bible
2) Powerscore Games Bible
3) NOVA Master the LSAT
4) LSAC Prep Guide (forget the name off hand, but you do not need that book until the end of your study)
5) Tests (there are 52 tests total, most people usually use about 20 tests)
You can purchase these books new or used. If you purchase them used, then you can save a bundle, go look on www.ebay.com
or your local www.craigslist.org
Good luck. Just know that most people who do well on the test study consistently for four to six months. There are a few "rare" people who score high "naturally" without much study. If you are like most people, you will need to study and consistently prepare.
One of the reasons the students who take full length courses do well is because they do a lot of homework, usually 4 hours per class session, PLUS take additional practice tests at a rate of two per week.