I want to establish a connection between 2 PCs. Point is to practice in writing client-server applications and similar stuff. I've heard around, that I can access another PC in network by address like "Router IP:port number". Am I right or i got it wrong?

So how do I configure router to let connections to certain ports? And what would address look like, if I'm, say, connecting to 80 port on my home server?

P.S. Will be grateful for links to some tutorials on this matter, if any.