Help finding the IP address

Greetings! I've got t-online DSL through a LinkSys etherfast cable/DSL router with which two computers are connected. I'm trying to test my web site before I publish it and would like to log onto the IP address of the Suse machine where I have the web site stuff from my WinME machine. How do I find the IP address of the Suse machine so I can make this happen? I can do it through the ethernet connection but can't seem to find the IP address so I can do it through the Internet. Thanks Eric