I think you should first look at server programming.
There are 2 types or methods for sending data: TCP and UDP. TCP ensures that every single bit of data you send is delivered to the other side. However if you get dc just for 1 moment, you will need to reconnect. UDP doesn't do that. You can disconnect, but the data would still be sent to you, even if you are not receiving it.
You should just look at UDP programming, because it is best suited for games.
Take a look at this tutorial. It has some stuff with UDP. There are a lot more tutorials on the web http://www.youtube.com/watch?v=dHHu2zmXeuM&list=PLlrATfBNZ98cCvNtS7x4u1bZOS5FBwOSb