To score good marks in chemistry it is very important that your basics should be clear and your fundamentals should be strong.

It is very important that you refer your text books. You should be focus on the topics which carries more weightage in the exam.

Which is best book to prepare for chemistry totally depends on you are appearing for which exam.

If you are preparing for competitive exam you can go for OP Tandon for higher level you can go for Morrison Boyd and  J.D. Lee

You should refer previous year papers for your practice.

Good Luck!!