Learning the Unix Operating System: A Concise Guide for the New User (In a Nutshell)

Unix in a Nutshell: A Desktop Quick Reference - Covers GNU/Linux, Mac OS X,and Solaris (In a Nutshell (O'Reilly))

Learning Unix for OS X: Going Deep With the Terminal and Shell

The Linux Command Line: A Complete Introduction

LINUX: The Ultimate Beginner's Guide!

Learning the vi and Vim Editors: Text Processing at Maximum Speed and Power

Learning the bash Shell: Unix Shell Programming (In a Nutshell (O'Reilly))

Classic Shell Scripting: Hidden Commands that Unlock the Power of Unix

Macintosh Terminal Pocket Guide: Take Command of Your Mac