What could be better than a book put out by the people who actually make the test? The Official Guide to the GMAT is one of the best sources for questions. It contains questions that actually appeared on previous administrations of the GMAT. Even though you won't see these exact questions on the exam in the future, you can be sure you'll see some questions that are very similar.
A couple of notes of caution about this book, however. First, the explanations often do not give the best method for answering a question. The Official Guide tends to stick with a more conventional form of answering questions - which is often slower. Check out a prep course in conjunction with this book to get the maximum benefit.
If you want more practice with real GMAT questions, GMATPrep Software is another good choice. Comprised of actual questions that have appeared on previous exams, it contains two full-length practice exams as well as tutorials on various components of the GMAT. You can download it for free when you sign up to take the GMAT at mba.com.
Unfortunately, the questions for both products are pulled from the same pool, so you won't get an accurate score for the GMATPrep if you've already worked through the same questions in the Official Guide. Your score might be artificially higher simply because you’ve seen the questions before.
We consider all these products to be essential for most people studying for the GMAT. But for unique questions, similar to those you will see on the exam, you will have to look elsewhere for books that do not rely exclusively on previous GMAT material.
