I don't think LuckyKeefer is saying he has boh an iBook AND an Airport Extreme Base Station. I believe he is saying he has an iBook with an Airport Extreme CARD in it and cannot connect to his wireless router (the belkin...)
If that is the case....
He should initially physically connect his iBook via the ethernet port to a LAN (regular ethernet port) port on the Belkin and use the browser http address of his router that is probably somewhere in his Belkin documentation to 'set up" the router. Once properly configured, i.e., set for DHCP (if appropriate....some DSLs require PPPoE...), wireless security initially OFF, etc. Once you do this and make an internet connection, it is usually only a matter of turning on airport and disconnecting the ethernet cable to establish a wireless connection.