Hi cheekycheeky,
You ask a number of really important 'big picture' questions; the answers will depend a great deal on the specific Schools/Programs that you're interested in and how strong your OVERALL application is (including your GMAT Score). Many Business Schools expect that Applicants will have at least 2-5 years of quality Work Experience (again, the specifics will depend on the exact Programs that you apply to). Many GMATers spend 3 months (or more) of consistent study time before they hit their 'peak' scores. This is all meant to say that you have to consider how all of this meshes with your potential timelines going forward. For example, based on the relative importance of a strong GMAT Score (especially at highly-competitive Programs), an application deadline might not matter (re: if you don't have the proper GMAT Score - and you are less likely to receive an invite - then you might not want to spend all of that extra time and effort to apply at that point in time).
Since it sounds like you're just beginning your studies, then it would be a good idea to take a FULL-LENGTH practice CAT Test; you can take 2 for free at
www.mba.com (and they come with some additional practice materials). If you want to do a little studying first, so that you can familiarize yourself with the basic content and question types, then that's okay - but you shouldn't wait too long to take that initial CAT. That score will give us a good sense of your natural strengths and weaknesses and will help provide a basis for comparison as you continue to study. A FULL CAT takes about 3.5 hours to complete, so make sure that you've set aside enough time to take it in one sitting. Once you have those scores, you should report back here and we can come up with a study plan.
I'd like to know a bit more about your timeline and goals:
1) What is your goal score?
2) What Schools/Programs are you interested in?
GMAT assassins aren't born, they're made,
Rich