I am a science student, completed graduation with bioscience. I want to be a CS. suggest me some books for preparation

thanks tanima for A2A. 
but here is some suggestion for you.
the option that you are looking for seems very wrong. such a shift is not advisable and may hurt your career to some extent by costing you these years in learning the basic stuff now and starting from scratch. 
 rather go for some CAT or management field where you can better make use of your analytical and mathematical skills that you acquired in your graduation. 

now talking about the books. you dont have to worry about books. just stick to the material provided by ICSI and go through it thoroughly. nothing is impossible. all the best.