Airport Wireless Base And Pc Compatability


I have an apple G4 and an airport extreme wireless base but I want to allow a PC user access to the Internet but don't know how to connect them up. I did find a long set of numbers in the password section but don't know where to enter it and there PC has a whole linsky thing going on. Any advice or suggestions as to where to get the info. Or maybe the two things are not compatible!!!
Many thanks Aoife.