References

The previous RMO and INMO question papers and their solutions give a good indication of the levels and the types of problems that appear at the regional and the national level Olympiad examinations.

Many useful concepts built from high school mathematics are taught at various Olympiad camps.  Some notes from such camps are available here.

There are many books that can help students to prepare for Olympiad examinations.  We indicate here a few of them.

    C.R. Pranesachar, B.J. Venkatachala and C.S. Yogananda (Prism Books Pvt. Ltd., Bangalore, 2008)

2. Challenge and Thrill of Pre-College mathematics
    V. Krishnamurthy, C.R. Pranesachar, K.N. Ranganathan and B.J. Venkatachala (New Age International Publishers,     New Delhi - 2007).

3. An Excursion in Mathematics
    Editors: M. R. Modak, S.A. Katre and V.V. Acharya (Bhaskaracharya Pratishthana, Pune, 2008).

4. Problem Solving Strategies

    Arthur Engel (Springer-Verlag, Germany, 1999).

5. Functional Equations

    B.J. Venkatachala (Prism Books Pvt. Ltd., Bangalore, 2008).

6.  Mathematical Circles: Russian Experience

    Fomin and others (University Press, Hyderabad, 2008).

Many other interesting references are given in An Excursion in Mathematics.