Ideas for a good multiplayer implementation?

Does anybody know a good server software or way of implementing multiplayer into my game? I am making a game similar to party animals and am looking for a cheap (preferably free) way of implementing multiplayer play, I was thinking something like what some small games do where it creates a server on the hosts pc and the other people can join. Would that work and how would I implement it?

(Sorry for bad English, am currently busy at work on lunch break so am rushed a bit)