Depending on what experience you have already, I would recommend the networking for dummies book... Even though there is a lot of resources out there, that gives you the best general knowledge that I have found so far. If you want to step in to the advanced TCP/IP understanding, then I would recommend taking a few classes. Networking can be easy with all of windows Plug and Play features but when there is a problem or if you need a special configuration, then you really need experience and training to handle that situation.

-Austin