Where can I go to learn more about networking, servers, IT, and similar topics?

Part of the problem is, it's such a broad topic, or really even set of topics, that I don't really know where to start. Basically, I want to learn more about how the connections between computers work, and the general management of that, on a deeper level than I already understand it. And even though I know a little from tinkering around some, it's a very shallow and incomplete knowledge. This is mostly just for personal interest, so I don't think I want to take a full-fledged class or anything, but if there was a website or a well-rounded book or something that I could look into, that would be perfect.