Linda video covering bash with some different topics covered. Free if you’re at Yale.
More involved and detailed than we are, good reference as well.
Covers regex, bash, linux tools, python and databases. Excellent resource for beginner and intermediate users. Available as eBook too.
A neat web app that breaks down many linux commands and shows you what each bit means.
An interactive and real-time sandbox to test regular expressions on text of your choosing. It also does a good job of telling you what each part of the expression does.
An interactive online tutorial to start learning the powerful text
editor vim
Guide on learning and customizinge Emacs.
Modern cross-platform (runs on linux/mac/windows) GUI text editor. Free and Open source!