If you use Linux in your day-to-day work, then Linux Pocket Guide is the perfect on-the-job reference. The third edition features new commands for processing image files and audio files, running and killing programs, reading and modifying the system clipboard, and manipulating PDF files, as well as other commands suggested by readers. It also introduces some powerful command-line idioms that you might not be familiar with, such as process substitution and piping into bash.
Linux Pocket Guide provides an organized learning path for Linux use, rather than Linux programming and system administration. You’ll find options for the most useful commands, grouped by functionality. For novices who need to get up to speed on Linux use, and experienced users who want a concise and functional reference, this guide provides quick answers.
Also check out Daniel's next book, Efficient Linux at the Command Line, to boost your Linux skills even more.