How to get online servers???

I need to know how to add online servers to my FPS game i've been working on.
I would like to know how to do this because Im making a Multiplayer/Co-Op/Singleplayer Game
If you could tell me how to
-Patch files
-Create servers
-Load servers
The basics. Pretty much.
I know how to code the game but i have no idea how to code the multiplayer ._.

To make things easier give RakNet a try, they have a demo version I believe. Read up on winsock & TCP/UDP protocols.

Thanks if I can get the demo working I will try to find a full version. & btw mate cheer up