I found this book to be useful enough to give it three stars, but the NET test I took didn't have half the stuff on it. Mine had a lot of little, repetitive parts about how I take tests, how much stress I have, etc. It would have been nice if this book prepared me for those monotonous questions, but I guess that's something they want you to answer on your own. My test didn't have any of the sciences or spelling questions at all. So really, the only part that came in handy was the math, and even that had a lot of stuff I didn't need, but skipped the ratios as another reviewer mentioned, which I did need.
Another complaint is the CD, which is just a repeat of the tests in the book. I thought it would contain more sample tests. Still, it's a whole lot cheaper than the $30 tiny book they tried to sell us at the school to prepare for the test. I actually think it is a much better resource than the NET test for finding your strengths and weaknesses.
As far as actually helping you study for the NET, well, it's pretty much hit or miss depending on what your test is like. But it's still not a bad book.