Reference

Bash shell commands

pwd: print working directory

ls: list contents of directory

cd: change directory

mkdir: make directory

cat: send file or files to output (in most cases, print to shell)

head: output first parts of a file or files

tail: output last parts of a file or files

mv: rename or move a file or files. Syntax for renaming a file: mv FILENAME NEWFILENAME

cp: copy a file or files. Syntax: cp FILENAME NEWFILENAME

>: redirect output. Syntax with cat: cat FILENAME1 FILENAME2 > NEWFILENAME

rm: remove a file or files. USE WITH CAUTION!!!

git init: create a new local git repository

git status: view the status of your files in the working directory and staging area
git add: tell git to start tracking a file, or a series of files
git commit: save file changes from the staging area permanently to the project history
git push: upload all commits to a remote repository, such as GitHub
git log: show history of commits in reverse chronological order
git diff: show changes made to tracked files
git pull: download upstream changes and merge them into your local repository
git remote add origin: add a remote repository named ‘origin’, to upload changes to or download changes from

An author at Webtuu.com provided both a clear introduction to git for absolute beginners and a follow-up git basics and branching blog post
This recent Git guide for beginners covers the basics and includes tips for both Github and Gitlab
For more in-depth coverage, Scott Chacon and Ben Straub’s “Pro Git” book is available as an online resource here

The GitHub help pages are a good place to start
GitHub has ‘activities’ which aim to explain how git works
GitHub also has interactive tutorials for their online version (Learning Labs) and for using Git offline (Git-It)
Atlassian has in depth and clear tutorials on using Git
“Dang It, Git” provides a great quick walkthrough of how to fix common errors for Git beginners