One wonders how you got in this situation....are you responsible for the server all by yourself?
If you really know **nothing** about Linux, then this is not really the best way to start.
Regardless--in addition to the links given above--take a tour of
http://distrowatch.com -----the most popular distros often come with a server version, and their websites may have some good info.
Finally, what have you found on Google?
