GMAT.. What is this test all about? Although it only covers English and Math, the big picture has much more to say.  As Princeton review rightly points out, to crack this test, you must be able to look at questions through the eye of the test maker rather than that of the test taker.   You are required to be good at your basics in Math and English grammar, BUT that’s definitely not all.

Understand what the exam intends to test.  Practice from genuine study material.  It’s easy to fall prey to the endless resources available on the Internet.  Understand that practice will help you to wade easily through the answer choices to the right answer.  That comes to you only when you know how to eliminate incorrect choices at a glance and solve smartly!  It is always better to stick to resources that give not only the solutions but their detailed working.

GMAT Official Guide and GMATPrep software make the BIBLE for GMAT.   Go ahead and solve from the supplement materials for Quant and Verbal from Official Guide(OG) for more questions. These study materials contain real GMAT questions that are retired from the database.  Get tuned to solving problems in the ‘GMAT Official Guide’s‘ way.  Once you fall into that groove, you can be sure that you are on the right track.  Ensure that you brush up on your basics and learn everything about the test; timing, number of questions, scheduling the test.. well before solving OG and I would recommend The Princeton Review: Cracking the GMAT to get an overview of the test.