Originally Posted by unSpawn
I agree that even a book from that long ago still serves a purpose as Linux server management as well as security insights and best practices tend to gradually evolve over time. However considering the topics of your previous threads (some of which unfortunately were left unanswered [0
]) which slowly move from client-oriented to server-centric, the fact you use a RHEL clone and the fact you appear to have started your server project some time ago I would nonetheless suggest starting with fundamentals like Rute's tutorial (just skip what you know) or if you want a dead tree O"Reilly's "Linux in a Nutshell" (2009 IIRC). While you might scoff at what the title suggests it offers you a solid foundation covering all Linux basics. But once you know how to properly config and admin a basic client role machine you're halfway there. One of the upsides of using Red Hat is that it comes with plenty of management basics (the Deployment, Configuration and Administration Guides for example) and server administration documentation you should be (or get) comfortable with anyway (RSN). A more recent (2011) dead tree might be Sobell's "A Practical Guide to Fedora and Red Hat Enterprise Linux" which covers firewalling and networked services too. Point is I wouldn't shell out cash because something is cheap. Instead I'd look around for what gets you up to speed with the basics in a comfortable and quick way (preferably something that you want to use and re-read again), check what's there for free on any topic that would get you started securing your server (about each major OSS has detailed sections on security) and only buy another book when you've exhausted your on-line resources.
I went back, commented and closed some of those threads.
I was able to get a copy of "Linux in a Nutshell" and am slowly making my way through it, along with the other book I mentioned above, on Linux network security.
Thanks to everyone for the suggestions, very helpful!
Looking back at my old threads, it's surprising how far I've come and how clueless I was, yet still am. I was lucky enough to be able to take an online grad-level course on Linux System Admin., using CentOS (hence my using it now.) It was very basic, however, so not much on iptables or (applied) security, other than basic principles/philosophy.
At this point I've made some progress and have other concerns I will start separate threads for. Thanks again to everyone that has helped me get this far.