webservers mainly, test, production, code testing, setting up filesystem for developers, setting up ssh for people to get on and sever support, maintenance and etc. Thanks.
Ja, then I'd load up Virtualbox with a couple CentOS instances and start playing. In fact, you might want to get yourself a RHCE book and go through that way. That'll get you up to speed in no time on what you need to know for those services ( really, those are pretty simple all things considered ), plus you can test for the cert if you feel so inclined ( a shiny for your resume ).