i have a lynksys 4 port router and i wanted to know how i set it up so i can host games online? do i have to forward the port to my ip? and if so, is it MY ip? or the one the router gives me?(192........) any help is much appreciated.thx

Take your router and make the game server computer on a DMZ port so you do not filter any gaming traffic. You will give the PUBLIC IP address you are given to your players...if they can PING this address, they can see your box. Your router MIGHT do NAT, whichever, it don't matter, but the gaming server should be on a totally open DMZ port.

you will have to set your router to point this traffic to your gaming server an example would be to allow traffic on 10910 to be routed to 192.168.0.2 you will first have to know what ports are required for the game you are hosting and map those ports to your game server DO NOT OPEN ALL YOUR PORTS TO THIS MACHINE as that defeats your firewall which is one of the lovely advantages of useing of a router.