Amazon.com just posted my five star review of Computer Networking: Internet Protocols in Action. From the review:
"I eagerly anticipated reading Jeanna Matthews' Computer Networking: Internet Protocols in Action (CN:IPIA). I am always looking for good networking books to recommend to people asking how to enter the digital security field. I am pleased to report that CN:IPIA is an excellent, hands-on, packet-oriented introduction to networking, suitable for all entry-level analysts. Even those with several years of experience may learn a trick or two, as I did."
This is a great book. I also learned that we can freely download copies of certain IEEE 802 standards from Get IEEE 802, like the ubiquitous 802.3 CSMA/CD standard. These are hundreds of pages long, and really only useful to hardware and protocol developers. However, if you need to reference an authoritative source, you can't beat these documents.