Missing something in "Network Setup"

[DarkNovember]

Probably because I haven't done it in forever, but I can't remember how to correctly set up a network in my apartment. My brother and I live in the same apartment, I'm hooked directly to the wireless router while he has the wireless NIC on his comp. He can get on the internet and all that just fine, it's setting up a network that we are having a problem with. I use the Network Setup Wizard and created a workgroup. I can see his comp on the network, but can't access it because I don't have permission. He ran the Network Setup Wizard, turned on file and print sharing, and change the name of his workgroup, and can't see my comp. What did I miss or what am I doing wrong?

Thanks