tell me to use books which are essential for iit and other exams?

let me tell you that no book till date has been published which can guarantee your selection in jee . books can only help .... so i would advise you to stop depending on a book and develop yuor application skills

one of my teachers used to tell me that if any of his student would tell him that he/she was solving a book for jee , he (teacher) would ask for the book and tear it to bits .. in front of the child .

but still if you want a book , only to improve your application skills .... better buy the previous yrs papers of iit-jee of any publication ... you can also try tmh

better join a classroom prog at askiitians