Hi konork,
Your question assumes that studying with a book is the best way to learn how to deal with CR. Many Test Takers who use a 'book heavy' study approach end up getting 'stuck' at a particular score level though, so you have to be careful about locking yourself into that way of thinking about your studies.
While you're asking specifically about CR, it's possible that you might need to work on additional areas besides that one category. Before I can offer you the specific advice that you’re looking for, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) How long have you studied?
2) What study materials have you used so far?
3) How have you scored on each of your CATs (including the Quant and Verbal Scaled Scores)?
Goals:
4) What is your goal score?
5) When are you planning to take the GMAT?
6) When are you planning to apply to Business School?
7) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich