zeusfaber, you wouldn't want to use a computer as a wireless access point. Your best bet would be to get a wireless router. That will give all of your computers Internet access through both wired ethernet ports and wireless networking. The router can also function as a DHCP server to automatically configure TCP/IP in all of your computers.
In theory, I guess you could attach a wireless access point to one of the 2 ethernet network cards in a computer that has 2 network cards. Plug your cable or DSL modem into the 2nd network card and use the ICS( Internet Connection Sharing) feature of Windows 2000/XP to give your wireless computers Internet access. Using a wireless router would still be the best way to go, IMO.