Hi Semusal,
Since it sounds like you're early-on your studies, then it would be a good idea to take a FULL-LENGTH practice CAT Test; you can download 2 for free from
www.mba.com (and they come with some additional practice materials). 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 4 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.
With a May 24th Test Date, you have over 3 months of potential study time remaining - which is good. You'll have to be commit to a consistent study routine to hit your score goal though (and that 3 months will pass by faster than you think it will). The books that you have are still relevant, but many Test Takers who use a 'book heavy' study approach end up getting 'stuck' at a particular score level, so you'll likely end up needing to invest in some non-book resources.
GMAT assassins aren't born, they're made,
Rich