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.

a decent server OS
Just use XP or something
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Now as for the wireless setup, I already have a wireless router connected to our cable modem.  If I drop in a WLAN card, do I just need to share the folder as >>2 said, or is there anything else I need to do? 

I basically want to set this up as a standalone server that never needs anything done save for powering it on.  I'll probably set up a firewall that denies all Internet access for safety's sake.  I don't want to run AV software or anything so it can constantly just share, share, share.  Is this advisable? 

>>4
No, that ought to do it. Make sure you set the access permissions right for the shared folder and you should be fine. AV software would be wise though - there are worms that can spread via network shares, so if one PC on your network gets infected it could spread to the media PC. Just stick AVG Free on there with auto-update, and allow it to be the only program that has access through the firewall. You might also want to put something like TightVNC on there so if you do need to do some work on it, you don't need to scrabble around the back plugging in keyboard, mouse and monitor - just control it remotely from another PC (though it's a bit sluggish over wireless networks due to the lower data rate compared to wired).