When it comes to preparing for the GMAT there is a voluminous amount of prep material available. Sometimes the material is so overwhelming that it becomes tough to pick and choose material to suit different parts of your GMAT Prep. To make life simple let us take up this topic in alignment with the structure I suggested for your GMAT Prep in this post. After you take the OG Diagnostic test to identify you learning needs, the three distinct phases of your GMAT Prep are Prep, Practice & Testing As someone who has prepared for and taken the GMAT myself, I can vouch that there is no prep material from any one brand that is best for all three stages.