[2005] Where to start to learn networking?

I'm using Visual Basic.Net. I'd like to learn how to start networking games, programs and such. My main goal is to make a multiplayer network game. Could someone point me in the right direction to a source(s) for networking? I really don't know where to start. Thanks,

Christian

The System.Net namespace is where you need to start, this is used for networking in VB.NET google it for info.