This installation isn't as involved as Anaconda. You just need to navigate to the Atom site and download the version of Atom corresponding to your operating system (Windows or Mac OS X).
Once you are done installing it, double check that it works by opening the Atom editor. I suggest creating a desktop shortcut for Atom or pinning it to you taskbar for easy access. We'll be using it a lot.
Once you are done installing it, a window should pop up that allows you to move it into your applications folder. I suggest doing that, and then also putting it down in your dock for easy access.