Command Line Workshop
This workshop teaches the basics of the bash shell. Many of the commands are similar in other shell environments, but they aren't covered here.
On Mac OSX, which is based on a Unix environment, you can use the built in terminal program (found in the Utilities folder of the Applications folder).
Windows, which is not Unix based, does not come with a bash shell. Please install GitBash.
Learn Enough Command Line to Be Dangerous by Michael Hartl, covers similar material to the two resources above.
Conquering the Command Line by Mark Bates is organized by command with subsections organized by the options for the commands. Makes for a clear reference with easy to navigate table of contents.
Command Line Bootcamp: an interactive tutorial in your browser, with all the essentials, by Richard Smith-Unna
Udacity: Linux Command Line Basics: videos and quizzes
Code Academy: Learn the Command Line: interactive, online tutorial; you can access the basic content for free, but not the exercises. A good, quick introduction to the basics like listing files and changing directories.
Practical Unix: good reference for learning lots about using the command line environment, beyond what is covered in this workshop.
The Art of Command Line: tutorial and reference to teach you the most common commands and tasks, with an awareness of differences with Mac and Windows
Bash scripting is not usually part of the intro workshop; it's an intermediate to advanced topic.
Bash Guide for Beginners by Machtelt Garrels is a bash scripting book/tutorial with exercises.
Shell Scripting Tutorial for writing bash scripts.
commandlinefu.com: user submitted command line snippets to do specific tasks. Be careful with these though and only run commands you understand to avoid doing bad things to your computer.
Mac OSX Snippets: useful shell commands specific to Macs. Again, be careful.
Awesome Shell: A curated list of awesome command-line frameworks, toolkits, guides and gizmos.
Cheat Sheets/Reference Sheets
Command Line Cheat Sheet with just the essentials, plus short explanations of key concepts
Linux Command Line Cheat Sheet: another useful version with the essentials, plus some intermediate commands
vi Handout: handout from the workshop
vi Basics: a good short intro explaining vi and a list of common commands, with the key commands highlighted.
VI Cheat Sheet: for using the VI command line text editor
Bite Size Command Line by Julia Evans -- a short zine with essential commands. Buy it for $10.