Get the following:
Official Guide-11th edition (you got to buy this book)
Official Guide-10th edition (avl on internet..can be downloaded)
Verbal Review (buy it later depending upon ur progress)

make a plan to study between2-3 hours on weekdays and 6-8 hours on weekends. If you miss anyday, make it a point to cover in same week.

take diagnostic test in OG-11 to understand ur strengths and weaknesses.
having done that, start with weakest area.
Always try to see what are the mistakes you have done and learn from ur mistakes. That way your accuracy will improve.
In later half of the preparation, say Dec onwards, try to solve in timed conditions.
All the best!