How do I set my pc's to a fixed network ip and still access the internet?

All of my pcs are running XP. I wanted to set them to fixed ips because one is running apache and I forward port 80 to that pc. It's a pain to keep going in the linksys router and changing the network ip. Anyways... I don't know much about networking. I unchecked the 'obtain ip address automatically'... I put in the ip address i wanted wanted 192.168.1.111, i entered 255.255.255.0 for my subnet mask, i entered 192.168.1.1 for my default gateway... All of this seems to work... people can access my webserver on my network or outside... the only problem is i cant access the internet now on that pc... i'm guessing its because i didnt fill anything in for the 'preferred dns server' / 'alternate dns server' on the same screen that i entered those other ips... i'm just not sure what to put in here...

any help would be appreciated... thanks...