Linux Shell Guide
A.R.F.A Labs
The Command Thesaurus
Say what you want to do. Find the command that does it. Unicorns are not included, but they are mentioned.
Manual
Open the book and type in the search box. Words like delete, copy, stop or add to a file find the right command. Click a command on the index page to turn to its entry. Each entry shows what the command does, what to type, what you see, other words for it, and related commands you can click through.
To try the commands for real, download guide.sh, run bash guide.sh, then type a word to search or a number to run that example in a throwaway folder. Type q to leave. Nothing outside the throwaway folder is touched.