The best book i would suggest for making yourself stronnger in solving the problems of mathematics is the book by M.L.Khanna and there are other books now a days which are very good for example the books by R.D.Sharma, R.S.Agarwal and so on.
						

							You need to join only 2 test series at maximum. Test series should make you practice well giving you full experience of real time IIT JEE questions and environment. Its important to analyze tests. Practice the questions which you were not able to solve during the tests again and again and last but not the least do quality work rather than quantity work. askiitians also provides the test series which is maintained by the experienced experts. you can feel free to join these and get the services by online.
						

							Could you please tell me how the book " Logical approach to modern organic chemistry " written by Jagdamba singh and s. anandavardhan is?

i already have a copy of that book with me and am solving from it.