Server Question: How do I turn a spare computer into a personal SMP MC server for me and a few (3-5) friends?

I play on a windows 7 gaming machine (gtx285, 6gb ram, core i7) but I have a macbook pro c2duo that is free to become a server. Your advice/links would be appreciated. Thanks :)

EDIT: I've got my own website Thinkpadius.com can I make that the minecraft server for me and friends?