If you are trying to decide between this Princeton Review book and Princeton Review's Cracking the SAT, which is very similar, my advice is to go with Cracking the SAT even though this is also a good book. I totally agree with Princeton Review's blurb that nothing prepares you better for the real SAT than taking lots of practice exams. The problem is that, with a few exceptions, these are NOT "real" SAT questions, but are instead Princeton Review questions that are similar to those on the real SAT, but not as well-written (nor as hard) as those on the actual SAT. If you want to prepare for the SAT by studying actual SAT questions, the only book that has them is the "Official SAT Study Guide," which is put out by the test's maker, the College Board. The Official SAT Study Guide features 8 complete examinations from previously administered SATs that are essentially identical to the test you will be taking.
If that were the only difference, buying the Official SAT Study Guide over the Princeton Review book would be a no-brainer. But it's not that simple. Unlike the Princeton Review, the Official SAT Study Guide does not provide explanations, but merely an answer key, which could leave you scratching your head about why the answer you picked was wrong, or how you were supposed to figure out the correct answer in the first place. You can get the College Board's "official" explanations for "free," but you have go to its website, type in a code key from inside the book, enter your answers in various and sundry boxes on the website, at which point you will finally be allowed to view the official explanations. By contrast, the Princeton Review provides explanations for all the questions right after each test, which means you don't have to go to hunting for them afterwards. Such convenience makes it much more likely that you will read the explanations, which is a very good thing.
Unfortunately, the Princeton Review answers, like the Princeton Review questions, are rarely as edifying or as helpful as those from the College Board -- -- in fact, some of them are downright confusing. So it's a trade-off. If you think you will take the trouble to go to the College Board website to get the answers, use the Official SAT Study Guide; if you have your doubts, go with Princeton Review and use their questions and answers, keeping in mind that they are occasionally murky, confusing, or even incorrect.
Personally, I feel that Princeton's own Cracking the SATs is a better book than this one because its practice drills and tips are brilliant (Joe Blog, etc), and still includes three full practice exams, even though its tests have the same problem as those in this book. (Note, however, Princeton Review's exams are superior to those of Kaplan and Barrons, which isn't saying much.) Overall, my recommendation is to buy Princeton Review's Cracking the New SAT 2008 to get the benefit of its excellent coaching advice, and then get a free copy of a genuine SAT when you register for the SAT. (Complete explanations for the practice test are also available on the college board website.) If you think you need more practice, consider buying the Official SAT Study Guide and use it with the materials provided on the College Board website. That should maximize your chances for doing the best you possibly can.