Linux Firewalls Written by Robert L. Ziegler.  Published by New Riders. Great book! Got broadband at home? Want a free firewall by using your old pc that is collecting dust for ages? Here is your answer. This book has lots of details of how to build a packet filter linux firewall based on ipchains. The author shows the examples of his scripts and this is how your scripts should look like. It starts from the very basic to a complex setup. Note: this book only focus on threats from the outside, not from the inside!!!!!!!
		Linux Essential Reference Written by Ed Petron and Laurie Petrycki.  Published by New Riders. Another great Linux command line reference book. This is a one stop shopping for man pages!  If you wish to configure and run Linux from the command line, or lazy of typing man pages on an terminal, this is the book for you. But if you are looking for tutorials, look somewhere else.
		Learning Red Hat Linux Written by Bill McCarty.  Published by O'Reilly. An excellent book for those who are new to Linux. The author explains the process of installation in plain English. You will have Linux running in your machine in no time! It also talks about the basics of the post installation such as: installing and configuring a web server, shell scripts, etc... If you want in depth knowledge of Linux, there is a sequel: Running Linux by the same publisher.
		Running Linux Written by Matt Welsh, Matthias Kalle Dalheimer, Lar Kaufman.  Published by O'Reilly.  A sequel from Learning Red Hat Linux! This is probably the best reference book that I have ever found! An excellent reference book for newbies to gurus alike. You can't go wrong and you will not regret. One thing that I like the best about this book: troubleshooting or what to do when problems surface.
		Red Hat Linux 6 Unleashed Written by David Pitts and Bill Ball.  Published by SAMS.  A must have! Why? This is a great reference book for people who want to experience Red Hat Linux for the first time. Also great for intermediate users but not for advanced users. It contains detailed installation instructions to get you up and running. It also explains all the tools that come with Red Hat for personalizing it and shows you what you can use the system for.