hi,

see ncert books and its examples and exercises are best for building the basic knowledge and 12th course preparation. however jee main exam is competitive exam and the nature of questions is mcq type. so you may expect questions from any of the part and based on the last three sessions exam questions are moderate level to tricky . so your basic conceptions should be clear and you have to make fast to solve the numeric problem with in given time. another thing you have to keep in Mind that try to make less of negative marks by giving incorrect answer. you should atleast practice the previous years papers of jee main.

hope it would help.