Linux

From Amazon.com:
Linux Unleashed, Fourth Edition, is for the professional who has experience with operating systems but is new to Linux or has limited Unix/Linux experience. The book focuses on the needs of administrators, power users, and programmers--covering everything from managing users and groups to using the programming tools that come with Linux. The book will show the reader how to install, configure, and manage Linux. The book will show the reader how the operating system works from the inside out. The book contains extensive coverage of the programming tools and utilities that help the administrator and programmer perform their tasks more efficiently.