The Official Guide for GMAT Review

The secret for the GMAT is practice and stamina.

For my own preparation, I used The Princeton Review, Kaplan's Book and ETS' The Official Guide for GMAT Review.

I will go through the advantages and disadvantages of each, and explain why The Official Guide for GMAT Review was the best of the three and why you should give it more time than the others.

Princeton:
Plus
- Good review sections (both quantitative and verbal)
- Practice tests similar to the GMAT
- Online tests are easy to review
- Provides you with a test strategy on how to crack the questions
- Explicitly advises you to practice also with The Official Guide for GMAT Review
Disadvantages
- Does not explain why a choice is wrong
- Not enough practice questions

Kaplan:
Plus
- Good quantitative review sections (appendix was great)
- Interactive software for reviewing the Kaplan GMAT strategies
- Practice tests similar to the GMAT
- Practice tests and sections are difficult, this creates in you a sense of urgency
- Plenty of practice questions
Disadvantages
- The software interface is old and slow, you are left to work with a little box on the screen
- Practice tests and sections' answer choices are not very well explained
- The questions are far fetched and do not fall in the spirit of the GMAT, this might lead you the wrong path

The Official Guide for GMAT Review:
Plus
- More than plenty of practice questions
- You might get the same or similar questions on the GMAT (like I did)
- The practice questions are organized by level of difficulty, the last ones are the most difficult
- Free PowerPrep software that has two practice tests exactly similar to the GMAT in look and feel (free online tests at the mba dot com website http://www.mba.com/mba/TaketheGMAT/Tools/PowerprepSoftware.htm)
- The practice questions reveal actual GMAT test patterns
Disadvantages
- Absence of test taking techniques
- The skills review sections are poor
- Only the last 200 questions in every practice section will be like the ones you will see on the GMAT (unless you perform poorly)

This Official Guide from GMAC should be the cornerstone of your preparation, simply because the questions are from past tests and are very thoroughly researched. This will allow you to develop insight into the test mentality.

Equally important the correct and the wrong answer choices for each question are explained in detail. You will learn the various ways used to lead you in error and consequently, you will develop the feel to spot and eliminate wrong answers.

The rules of grammar on which the GMAT Sentence Correction questions are based are best outlined in this guide. I had a lot of difficulty with the Verbal section until I read through the explanations here.

Overall, this book shows you all the tricks of the GMAT. I did not have bad surprises when I took the actual test; it seemed that I had seen all the questions before.