The installation is quite simple as there are seperate installers for MacOS and Windows machines available here. Currently two versions are for download: one beta and one stable.

Setup will start after you downloaded the program and you´ll need to login with your GitHub credentials. That is really the only step because after that you can start to create a repository or clone one.

Note: during the installation not only GitHub Desktop will be installed but Git too. So you don´t need to install it seperate.

As it is with GitHub Desktop most of the work is pretty simple: You select "Clone a repository" (In the stable version the plus on the upper left) and there are some repositories (your own and the repos from each company you are in) recommended. Alternatively you can paste a link to any other repository you might want to clone.

Note: in the newer version (beta) there are no (not jet?) recommendations.

You can select a branch at the upper left. When you selected the right branch you need to press the sync button (upper right) which does now the same as git checkout BRANCHNAME.

In the older version you are able to view 2 different branches at once and compare the pushes. Furthermore you could view a timeline of your project (see beneath)

Creating a new branch

You can create a new branch by clicking on the branch symbol (old client) or under File --> New Branch.

Note that you can select of which branch the new branch uses as base by clicking on the branch name.

Pull (Sync)

Like in the command line you need to pull the current state of the repository once in a while. In GitHub Desktop this process is called by the sync Button at the top right corner.

Push

When you made local changes and want to push them you make a commit by writing something into the summary textbox. Then you press Commit to YOURCURRENTBRANCH. Now you´ll need to press the sync button and your push is made.

Note: You can use emoticons, mentions and referals to other commits or issues directly from the textbox.

So the Sync button can be used to Push,Pull or Checkout.