I have the TCP/IP Guide you mention and I'd recommend it, also. I'd also suggest if the asker buys the Interconnections book, that they also go ahead and buy the TCP/IP Illustrated (volumes I-III) as well. They are textbooks, to be sure, but if you find this stuff interesting, you'll be happy to have them. Very high knowledge density, though a bit outdated. And while we're talking about some of those old textbooks, I'd recommend the newest editions of the Unix Network Programming books [0], the earlier editions of which were really helpful to me when I was learning this stuff way back in the day. I'm a huge fan of textbooks, so maybe I'm going a bit overboard, but I did really enjoy them.
Also by the great W. Richard Stevens is Unix Network Programming (http://www.amazon.com/UNIX-Network-Programming-Networking-Sockets/dp/013490012X).
If you want to learn about sockets and the server side of that, try Stevens, Network Programming.
http://www.amazon.com/UNIX-Network-Programming-Networking-Sockets/dp/013490012X/ref=sr_1_1?ie=UTF8&qid=1310677130&sr=8-1
[0] https://www.amazon.com/gp/product/013490012X/