I had a similar problem, although I was just networking two PCs with wireless cards and without a router. My laptop and PC resolutely refused to see each other, although the wireless utility told me the network was there. I did a couple of things that sound obvious, but after I did them, everything burst into life:
a. Make sure that you have File and Print sharing enabled on both machines (Control Panel, Network Connections).
b. Actually share a folder. Unless you do this, Windows won't see anything.
c. At this point, I still wasn't seeing anything so I went to Search/Computers or People/A Computer on the network. In the search field, I typed *.* and pressed Search. As if by magic, the computers showed up.
You may find that your wireless connection is a bit "blocky" - that means that the computers will take a few seconds to find each other, and that even after the connection has been made, it will seem to drop out every now and again. But once you have the shared folders in your "network places", you should be okay.
To put folders in network places (or to map as a network drive), you need to use the convention \\computer name\share name.
I hope that helps