Starting in multiplayer

So I have a game I want to upgrade to multiplayer. I have no past experience with servers so I’m a complete noob. I want to model my multiplayer structure after this game.

This means I want to let the users set up their own server that they and others can play on. This way everything is handled inside Unity and they can’t be a shortage of servers. Would this be local or peer-to-peer? Can someone point me in the right direction to look at some tutorials or documentation?

try this link which will help u.
http://forum.unity3d.com/threads/29015-UniKnowledge-entry-Unity-Networking-the-Zero-to-Hero-guide