may we can make a list of all websites offering free material - some i know of:

www.tenaday.com 

www.yesican.co.in

etc

any more?

Ofcourse there are some really good websites which help u in preparation. The biggest advantage is that u get to interact with various aspirants and get to share knowledge and opinions. If you get stuck on any question, u can post in the forums and other aspirants can answer the question almost immediately.

For example, there is this site CHALO BOLO which provides latest news about what is happening in education sector, latest B-School news about courses and placements. Chalo Bolo also provides free online Mock tests based on real pattern,, and also free GK tests...

All in all, these websites are of great help.