Chemistry: Modern's abc of Chemistry for CBSE Class XI, Class XII by Dr. S.P. Jauhar
Mathematics: Objective Mathematics for IIT JEE by R.D. Sharma
Physics: Concepts of Physics by H C Verma
All the recommended books have ample practice problems and questions
Additionally you can acquire TMH practice books. It is preferable to buy when their JEE 2011 books are published. You can borrow 2009/2010 books from your seniors or try to buy them from second hand book stalls.
You can acquire past chapter JEE problem/questions books of MTG.