Lisa,
Have you had a look at
http://www.microsoft.com/technet/com...uy/cg0804.mspx - a Microsoft guide to WLan config on SP2.
IIRC, on the desktop you will need to add a 'prefered' connection and as well as specifying the SSID (Network name) and WEP key you need to select 'This is a computer-to-computer (ad-hoc) network' at the bottom of the page. This will tell windows to broadcast the SSID as well as listening for one.
It should be much easier when you get your router!
HTH