hi,

see now a days there is many books available on pdf version or in kindle edition. however if you are comfortable to read pdf you may study as well. however not all of the books can be found in pdf version. you need to purchase questions papers or  other study materiel as per the requirement of your preparation.

another most important thing is you have to practice a lot, its not that you just read topics and left them aside. to get a decent score you have to give mock practice exams in home which makes you faster to solve the questions.

hope it would help.