LSAT PrepTests are actual, previously administered LSATs. For pure practice at an unbelievable price, you can't beat 10 PrepTests for $29-purchased individually, these 10 practice tests would cost $80. Each test includes an answer key, writing sample, and score-conversion table.
There's just no substitute for the real thing. Take the full tests, under actual timed conditions, and do it over and over again: that's the single best way to know if you're really ready.
The only negative for this particular book is that the tests are older, and so not quite as close to how the test is today. Fortunately, it hasn't changed all that much, but if I were to do it over again (please, god, no), I would buy the most recently published collection and work from that, but the practice was invaluable, no matter what.
One star for enjoyment, five stars for effectiveness. You really should practice using these full-length tests. The more tests you take, the more prepared you will be when you sit down to take the real deal. Good luck!
This edition may not be as relevant as the most recent counterparts for it doesn't include the comparative reading section. Still, a reader can get plenty of practice.