The Official Guide for GMAT Review, 11th Edition

If you're taking the GMAT, you must work through this book. I made the mistake of buying every study guide out there (Kaplan, Princeton Review, Barron's...), but on the day that I walked into the test center, the Official Guide was the only book that I had used.

I took the GMAT a single time and scored a 770. Here's how I did it:
1. I bought the Official Guide.
2. I bought Jeff Sackmann's two e-books, The "GMAT Math Bible" and the "Official Guide to GMAT Review" and used them to work through each problem in the Official Guide.[...]
3. When doing a set of problems from the Official Guide, usually 10 to 15 at a time, I timed myself. Anytime I took longer than 2 minutes to complete a a problem or I got it wrong, I read Sackmann's explanation and re-did the question from scratch.
4. I worked through the Math Bible methodically, trying to do at least one full chapter a night.
5. Six weeks before I took the test, I[...] This is the official site of the GMAC, and the only place that you can access these two practice tests that use the same scoring logarithm as the actual test. Two weeks before my test date, I took the second practice test.

All in all, I spent about two months studying for 1-3 hours a day - and I work full-time, so it wasn't easy. But it was worth it. You *need* the Official Guide if you're studying because it's the only resource with actual questions from the GMAT. The rest of the books out there use made-up problems and many of them aren't very accurate. Because the Official Guide doesn't rate each problem's difficulty, you should consider a companion book (like the ones mentioned above) that rate the problems and offer better explanations.

This is such a great study tool. The questions and answers are GREAT! The answers walk you through each question in detail, as well. Purchase this book before you pay for the GMAT Prep Class!

She tells me this will help tremendously but results will not be known for several months when she actually takes the test.

No matter what you read or don't read, this book is a must for all those who prepare for GMAT. Though some of the explanations/concepts are not so well written, this book has the "REAL" content. Most of the questions listed in this book are supposedly taken from previous GMATS. And that explains why you see such a similarity between problems/questions in this book and the real GMAT ones.

Having said that, just this book alone will not be sufficient for most of the people as there is a very less emphasis on explaining the basic concepts. I recommend using Princeton and/or Manhattan series books as a supplement to brush up the fundamentals and then use this one for practicing GMAT-like questions.

This book can't be beat if you're looking for a book that will give you an overall picture of the format of the GMAT. The book contains questions for all the math and verbal sections as well as providing essay examples.

Another benefit of this book is that the questions are real questions from past GMATs. I think this is especially helpful in the verbal section as it is difficult for other authors (Kaplan, Princeton Review) to create realistic verbal practice questions.

Use this book to get some great practice working a whole lot of real GMAT questions, but if you are looking for a book that helps you re-learn math concepts and has more of a textbook feel, look towards Kaplan.