Most of the network monitoring is self taught. If you sat down at his console, I bet you would not be able to understand anything there when he is monitoring the network.
Did you want to understand it, or did you want to just get a broad understanding of how networking works?
If you want to understand everything, I would suggest a Cisco networking course, like CCNA.
If you are just looking for an understanding, then I hate to say it, but I think your best bet is to start off with a book like "Networking for dummies", and I would highly recommend that you learn about the OSI model. You won't go anywhere in networking without knowing about that. (have you ever heard anyone say "Layer 2" or "Layer 1" or "layer 3", etc.? that's the OSI model they're talking about.). After that, you should have an idea about what you want to know more about.