Wireless media server

I'd like to throw together some parts and turn my 200gb USB IDE hard drive into a wireless media server.  Can this be done with a basic old setup (1-1.4ghz P4/Athlon XP, 256 megs DDR, a decent server OS) and a PCI wireless card? 

Anyone have any good FAQs for a complete server n00b? 

Yeah, sounds about right.  Just use XP or something and right-click the folder for the media, go to Properties, and share it on the network.  That'd be the easiest way I can think of.