I'll bite, I used to have this on an old iBook G4 before airport cards came installed by default.
If you goto here and then goto the drivers page, you should be able to download the drivers, obviously if the wireless isn't on do it using a wired connection or on another computer then put it onto a usb stick.
From memory this is an installer that requires you to reboot, once you've done that you goto System Preferences (Apple in the top left -> System Prefs) and it should be at the bottom under Belkin.