UNIX for the Impatient
I am a complete Linux NooB and I have been teaching myself Linux as I go. I am working with RedHat 9.0 .
Part of my Uni course I have to leanr about Software Development Tools, and that involves using Linux, although they wanted me to use RedHat 7.3.
The complulsory book for the subject is:
Unix for the Impatient Author: Paul W. Abrahams and Bruce A. Larson
This book is exactly as the title suggests - I mean it is working it's way from the basics but for someone who knew NOTHING about Linux, it has been a godsend.
It might not go to the detail about teaching you about Network Security - but it is definately a start.