Hi selserougi,
For someone who's just beginning their GMAT studies, I recommend a 3-month Study Plan (regardless of the materials that are used). During that time, you should plan to study 10-15 hours per week and take practice CATs at regular intervals (but no more than 1 per week).
As an individual's goals, available study time, prior study, etc. vary, the Study Plan could also be adjusted. The GMAT is a big part (and in many cases, the BIGGEST part) of the application process; it affects the steps that come after (scholarships, applications, sometimes even job interviews), so you have to be prepared to put all of your best efforts into the process of studying for the Test. You also have to make sure that you have the proper guidance and resources to succeed.
Since Business Schools don't really care if you take the GMAT more than once, everyone has the opportunity to study as they see fit. For example, if you put together your own plan and earn a GMAT score that puts you in range of your Top Choice B-School, then great. If the plan does NOT work, then you can come up with a new plan - it will just cost more time, money and effort - and you might have to change your application plans.
Most Test Takers don't know enough about the intricacies of the process to score 700+ though. That's why GMAT Companies are here.
If you'd like some more specific information that will help you with your plan, then you can feel free to post it here or you can contact me directly.
GMAT assassins aren't born, they're made,
Rich
