Hello,

There are numerous books  for Mba coaching nowadays.But one thing you remember while preparing that no doubt hardwork is necessary but here smart work is more important to score good in CAT.

Here is list of few highly recommended books-

QUANTITAVE APTITUDE

• How to prepare for quantitave aptitude by Arun Sharma
• Quantum CAT for common admission tests by Sarvesh Verma
• Rs agarwal for aptitude
• Arihant Publications 

ENGLISH VOCABULARY

• Word power made easyby Norman Lewis
  
• High school grammar and comprehension by Wren and Martin
• Students' companion by Wilfred D Best

DI AND LR

• Logical Reasoning by Nishit k Sinha
• How to prepare for Data Intepretation by Arun Sharma
• How to prepare for Logical Reasoning by Arun Sharma

Verbal Ability and Reading Comprehension

• How to prepare for Verbal ability and reading comprehension by Arun Sharma
• Verbal and non verbal ability by Rs agarwal
• Verbal ability and logical reasoning by Nishit k Sinha

So here are some best books to score good.You can choose accordingly whichever suits best for you.

All the best for your future!