How do I prepare myself for CAT?

A friend of mine prepared for CAT by himself in 6 months. He followed the set of four books authored by Arun Sharma (one each for VARC, DI, LR, and QA) and Word Power Made Easy by Norman Lewis.  He was weak in Verbal. So, he started reading as much as he could. It eventually paid off well, since a large part of CAT Verbal is Reading Comprehension. DILR is all about practice. He practiced as many questions as he could to feel confident in this part. He had one month left to prepare for quant. He started giving mocks along with his preparation. Although he couldn’t cover the whole Quants section, he scored around 98.89% and was selected for IIMA. 

So, you need to evaluate the time you have and formulate a strategy that will serve you well.