Faith +1 mentioned this first, I just wanted to expand a little bit. Faith +1 said to use a broad band router as the dhcp server on your network, and of coarse you realize hes refering to a cable/dsl router found in all walmart / tech stores, but if you don't have one lying aroudn I would recomend buying on off the net.
While I'm not a big fan of this newegg.com , manny people have been very happy with them, and after looking at their site tonight they have several routers under $25, and they have 8 port switches under $20, I think they had one for $13 or $14. So if you bought the router and switch you could have up to 11 people conected and the router would handle all the IPs for you, if you bought the 5 port switch you could have up to 8 people conected... The thing to keep in mind, and I think you already had a general idea of this, is to not use a hub. Hubs create a lot of un-needed network traffic, and they could cause major havic to your games by not giving you the needed performance.
Hope this helps,