You're learning VB so I'm assuming you're on windows.. MSDN has tons of info..

If you want to learn about networking, start at home..
Get another machine and network them.. Learn about TCP/IP, what it is and how it works.
If you cannot afford a new machine get an oldy, as long as it works..
Try a BSD or a linux distro.. That way you kill 2 or even 3 birds with 1 stone..
You'll learn about networking, another OS and more indepth knowledge on how things work...
Learn the basics and learn them well. You need to learn how to walk before you are able to run