Some very good, free Unix and Linux books:
- Introduction to Linux – A Hands on Guide
This guide was created as an overview of the Linux Operating System, geared toward new users as an exploration tour and getting started guide, with exercises at the end of each chapter. For more advanced trainees it can be a desktop reference, and a collection of the base knowledge needed to proceed with system and network administration. This book contains many real life examples derived from the author’s experience as a Linux system and network administrator, trainer and consultant.
- UNIXhelp for users
Helpful information for users of the UNIX operating system, developed at the University of Edinburgh.
- Linux Filesystem Hierarchy
This document outlines the set of requirements and guidelines for file and directory placement under the Linux operating system according to those of the FSSTND v2.3 final (January 29, 2004) and also its actual implementation on an arbitrary system.
- The Linux System Administrators’ Guide
This book covers all of the aspects of keeping the system running, handling user accounts, backups, configuration of the system, installing and upgrading software, and more.
- Linux System Administration Made Easy
The Linux Administration Made Easy (LAME) guide attempts to describe day-to-day administration and maintenance issues commonly faced by Linux system administrators.
- Linux Newbie Administrator Guide
Simple answers to problems that Linux newbies frequently encounter while setting up/using/administrating their computer or home network.