I need help with Linksys Wireless-G, ADSL router. (WAG54G)

I have a Linksys Wireless-G, ADSL router (WAG54G).

I can't get it to work with my TDC Broadband (DHCP), and i have tried everything i know.

do i really have to change over to PPPoE with TDC or can i do anything to get this DHCP thing to work with this router?

The main thing is, i don't want to use the white modem that comes with the broadband package, it is pretty useless to use that with the other router.

If that is not possible, how can i put the WEP key and the security in this router. There are no good explanations in the package...

thanks in advance for the help...

regards,
Gudjon