What next?
 

Just finished loading Virtualbox on computer, installed centos. Now what? Try'n to learn how to set-up a home based server, e-mail server all in one. I'm totally confused on where to begin this learning curve.

I would recommend to first learn the basic commands before going any further, so that following a tutorial is not only blind copy&paste, but you are actually understanding what you are doing.
Have a look here for that:
http://linuxcommand.org/index.php
http://linux.2038bug.com/rute-home.html

After you have done that, just pick a tutorial from the net for what you want to achieve, for example:
http://www.howtoforge.com/perfect-se...nx-ispconfig-3

Thxs
 

Thxs for the links. Just what I'm looking for, some where to start.

This is also a good site for HOWTOs for home servers http://www.linuxhomenetworking.com/