Teach Yourself Linux in 24 Hours (pdf) B.Ball - S.Smoogen (SAMS)
"This book is designed to help you learn quickly. You’ll find it an indispensable guide to installing Linux and getting right to work. This book helps you overcome technical obstacles, explains complex subjects in simple language, and shows you some neat tricks to make your computing experience easier". [3Mb]

Linux Administrators Security Guide "LASG" (pdf) Kurt Seifried
This guide is not a general security document. This guide is specifically about securing the Linux operating system against general and specific threats. [390Kb]

Linux Administration Made Easy (pdf) Steve Frampton
This documentation will attempt to summarize the installation and configuration, aswell as the day-to-day administrative and maintenance procedures that should be followed to keep a Linux-based server or desktop system up and running. [420Kb]

Get Acquainted with Linux Security and Optimization System (pdf) Gerhard Mourani
A guide for information system, configuration, optimization and network security professionals. [1.2Mb]

Guidelines on Firewalls and Firewall Policy (pdf) John Wack, Ken Cutler, Jamie Pole (NIST)
This document provides introductory information about firewalls and firewall policy primarily to assist those responsible for network security. [1.3Mb]

MAXIMUM RPM (pdf) Edward C. Bailey
This is a book about the Red Hat Package Manager or, as it is known to its friends,RPM. [1.5Mb]

Securing and Optimizing Red Hat Linux (pdf) Gerhard Mourani
A guide for information system, configuration, optimization and network security professionals. ver. 1.2 [2.6Mb]

Using Samba(pdf) Samba Team
A guide about installing, configuring and running a Samba server.