I will give you a subject-wise list of the "most" important topics, the ones which give you a lead. Pardon me and add if I forget some.

Physics:

Electrostatics & Gravitation(conceptually similar)
Current Electricity & Heat Transfer(conceptually similar)
Electromagnetic Induction

Waves (Sound as well as optics)

Geometrical Optics

Thermodynamics and KTG

Rotational Dynamics

Dimensional Analysis - Not a well taught topic but it can help you eliminate many options.

Mathematics:

Matrices and Determinants
Definite Integration
Vectors and 3D
Differential Equations
Conic Sections and Straight Lines
Basic Equation Solving(Trigonometric, Quadratic, Bi-quadratic)
Sequences and Series
Formulas of a triangle

Chemistry:

1.Chemical Bonding & the periodic table(the only chapter if done perfectly can clear most of your doubts in inorganic as well as organic chemistry) ==> makes it easier to learn Coordination Compounds and predict a hell lot of properties ranging from MP,BP, Solubility to reactivity, optical rotation and what not !

This chapter is a necessity if you want to learn chemistry.

2.Carbonyl Compounds & their derivatives

3.Redox reactions, Mole Concept & the concept of equivalents(they have multiple applications in equation balancing to predict the products of a reaction, electrochemistry, inorganic chemistry)

4.Solid state, solutions & gases theory

5.Thermochemistry & the Second Law of Thermodynamics

These should be your strong topics although you should go through others too atleast once.

Wishes !

the following link is for answer key
notes:- answer can be wrong so please dont loose hope :D
jee mains key

1.physics or click here
https://docs.google.com/file/d/0Bwb9j3hAO4PubkotUkg4LVJORHM/view?pli=1&sle=true
2. maths or click here
https://docs.google.com/file/d/0Bwb9j3hAO4PuWkszYktBTkhZc0U/edit?pli=1

resonance answer key for set E

Maths - Any good book will do, just as long as it has thousands of problems (I'm serious). But here are some of the books I know and have used:NCERT, Tata McGraw Hill, G. N. Berman, A. I. Prilepko, Hall & Knight, S. L. Loney.

Physics - Just three - NCERT, H.C. Verma and I. E. Irodov. If you want really challenging problems, try the Krotov.