GMAT Book 1 - The Official Guide for GMAT Review, 11th Edition (Paperback)
With an excellent selection of practice questions and a thorough explanation of the reasoning behind each answer, the 11th edition review is more than preparation for taking the GMAT. The book acts as a teaching tool, reinforcing concepts. The questions, which may be identical or similar to those encountered in the test, are arranged in ascending order of difficulty. Free PowerPrep software helps familiarize the student with the test format. More information about test-taking technique would be helpful.
GMAT Book 2 - The Official Guide for GMAT Verbal Review (Paperback)
Another study supplement for the GMAT, this book covers the verbal portion of the test and the questions are much the same as the questions in the official guide, and therefore pretty much the same as those students will face on the tests. The value here lies in the opportunity for additional practice. However, if you have the official guide, this one may not be worth the expense due to question duplication in the official guide.
GMAT Book 3 - Cracking the GMAT with DVD, 2009 Edition (Graduate Test Prep) (Paperback)
This is a great beginner's book, if you are entirely unfamiliar with the GMAT and its format and need to know what to expect. It definitely won't take the place of the Official Guide, and the DVD is very limited. The information is presented in a relaxed, friendly manner that is easy to read but seems more suited to a high school student. The test-taking techniques are useful and perhaps the best contribution this book makes.
GMAT Book 4 - Kaplan GMAT 800, 2008-2009 Edition [ILLUSTRATED] (Paperback)
Again, Kaplan provides additional practice questions for the GMAT test, but is weak on explanations of answers. Lots of guessing tips! In addition, they felt a bit too easy for realistic preparation. It's very readable, and the price, by comparison, is better than most GMAT guides. If you are scoring in the 700-750 range, you might as well skip this one. However, if you are struggling to get to 650, this will be a good place to start.
GMAT Book 5 - Critical Reasoning GMAT Preparation Guide (GMAT Strategy Guides) (Paperback)
Another of the eight-volume Manhattan series on GMAT preparation, this one offers a well-balanced and organized format. It presents arguments with clarifying illustrations that are well-constructed and easy to follow. Practice problems provide a good foundation for study. It is a bit expensive and advocates writing out arguments, which, if followed, is likely to take too much time, but overall a valuable resource for serious students. I recommend this book, as it worth every penny.
GMAT Book 6 - Kaplan GMAT Math Workbook (Paperback)
Not for people working at high levels of math expertise, this book offers much for most students. There are lots of practices problems that will help prepare the student. The book begins with very basic (but not remedial) levels and progresses through more demanding exercises. The book does contain a few errors and students should be watchful of those. The book is set up to move from basic to difficult and allow you to build on knowledge.
GMAT Book 7 - Kaplan GMAT 2009 Comprehensive Program [ILLUSTRATED] (Paperback)
At $23.00, this book is lower priced than some GMAT guides, but that's without the CD, which would double the price. It does include practice tests you can take on-line. This version includes all the topics offered in the premier version except math. For math prep, you will need another supplement. It still does not take the place of the Official Guides, but does work well as a supplement. I think the material is better presented than the premier version.
GMAT Book 8 - Barron's GMAT (Barron's GMAT Graduate Management Admission Test) (Paperback)
The publisher says this is a comprehensive preparation for the GMAT, and appears to live-up to its reputation. It does best in the math area, which may make it a good complement for the Kaplan Comprehensive, which lacks math. Offers many guessing techniques and if you expect that to be helpful, you can buy this book right away. Certainly, it's better to guess than to waste five or ten minutes on one problem. At $18.99, it appears to be worth the price.