Linksys and Airport with Ti Book?

[BigScanner.com]

Not sure what I'm doing wrong...
Here's my set up:

I have a Cable Modem hooked to a Linksys router.
The router goes out via Ethernet to a PC, a G4 and (hopefully) the Airport
Extreme (so I can use the Laptop in another room).

Do I just plug the Ethernet cable up to the WAN input on the Base Station?

I tried that and it didn't seem to want to connect.

Know of any good tutorials online for this specific set up?

Thanks in advance,
Terry