Hi SRH750,
When working with any type of print materials, the logical first step is to read through the initial portion of the book - so that you can get a better sense of its structure, tone, etc. From your post, I assume that you need to develop a number of different CR-related skills, but we won't know whether you need to complete that whole book or not until you actually do some work with it. This is all meant to say that you might find it best to get started with it and then we can see how well it is helping you to improve in CR.
Before I can offer you any additional advice for your studies, 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? How many hours do you typically study each week?
2) What study materials have you used so far?
3) On what dates did you take EACH of your CATs/mocks and how did you score on EACH (including the Quant and Verbal Scaled Scores for EACH)?
Goals:
4) What is your overall goal score?
5) When are you planning to take the GMAT?
6) When are you planning to apply to Business School and what Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich