The CD in the Sybex Security + books is "OK" but as Juridian said, don't make this your only book, or source. They concentrate on more practical study guide type things, when what you'll probably want is something like a mixture of Sybex and TCP/IP related books mixed with other security books. UNIX books are something you may want too look into too. I've learned more about networking from these than I have from "Network books".

It's a shame what you can get away with calling a book these days. The biggest problem with these types of books are misinformation. If something doesn't seem right too you, make sure you say something about it. I can't stand incompetent authors who breed on the money of the drooling half wits that read and believe everything in them.