Hi Vidhiduhita,
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 access 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 that Score, 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) When are you planning to take the GMAT?
3) When are you planning to apply to Business School?
Based on your questions, it sounds as though your immediate study plan is 'book heavy'; unfortunately, many Test Takers who study in that way end up getting 'stuck' at a particular score level. There's no harm in starting off your studies in that fashion (and you don't need to purchase any other 'versions' of the books that you have), but you'll likely end up needing to invest in some additional, non-book resources at some point.
GMAT assassins aren't born, they're made,
Rich