I think the very first thing you should ask yourself right now is "why you want this MBA"? What can this degree help you in terms of what you want to do? If you can't really answer these questions right now, think about them deeply. I wouldn't rush into the application stage - there's simply way too many things to think about (especially the fact that you haven't sat for your GMAT). Unless you're way over the average age of students in b-school, I wouldn't start my application just yet.
GMAT Club Premium Membership - big benefits and savings