Gold Medalist in B.Sc., IIT Kanpur Alumini , PhD. Maths, 4+ years experience with BE students
I can suggest about preparing maths for IIT. Preparing for maths does not means learning couple of formulaes and apply them. The basic concept should be very clear which means knowing how we got that formula so that if some tricky changes in the problem has been done, student is easily able to tackle it. Student should take topic one by one and start from the base, do not just pick books with heavy questions and start with them. Knowing a topic perfectly has three step: (1) know the basic (2) practice with simple problems (3) go on practicing with all kind of problems which fantasize you. At last there is no substitute to hard work. More problems you practice using pen and paper more comfortable you are with them.