Github switch between branches after cloning repo

git clone <somerepo> .
git branch -a // View all branches
git checkout -b <branch_name> origin/<branch_name>

Github cheat sheet

HEAD - pointer to latest commit

git diff <source_branch> <target_branch> - changes between 2 branches
git diff HEAD - changes with latest commit
git diff --staged - diff with staged files
git reset <file> - unstage <file>

Branch - the copy of project

git branch <branch_name> - creates branch <branch_name>
git checkout <branch_name> - switch branch to <branch_name>
git branch -d <branch_name> - delete <branch_name> branch

Merge - copy changes to current branch

git checkout <branch_name> - now we'r in the <branch name>
git merge <other_branch_name> - merge <other_branch_name> changes into <branch_name>

Update your local copy to latest:

git pull

Creating tag:
Tag is a software release (like in SVN)

git tag 1.0.0 b01a419cff

The b01a419cff is a commit id.

If something went wrong, and you need to replace changes:
git checkout -- <file_name> - replaces changes with the last content in HEAD.

If you want to drop all local changes and commits:
You need to fetch the latest history from remote repo and point local master branch at it

git fetch origin
git --hard origin/master

How git works:
1. Changes in local repo

git add --all

2. Changes in Index (staged)

git commit -m "Adding all files"

3. Changes in HEAD (commited, but still not in remote repo)

git push origin <branch_name> (git push origin master)

4. Now changes pushed to remote repository (master or other branch)

Usefull commands: 
Launches git GUI:

gitk

Information from:
http://try.github.io
http://rogerdudler.github.io/git-guide/