These instructions are specific to the Raspberry Pi 2 and 3
To get started I suggest a clean install of Raspbian. You can snag a fresh copy of Jessie w/ Pixel Raspbian Download Page.
Make sure to download the Full desktop image. Do not use NOOBS to install Raspbian.
For instructions on how to install Raspbian see How To Install Raspbian(full).
You'll also need to install Node (v6.x) which now comes bundled with npm.
curl -sL https://deb.nodesource.com/setup_6.x | sudo -E bash - sudo apt-get install -y nodejs
Getting the code
Next up you'll want to clone this repository into your user's home folder on your Pi:
cd ~ git clone https://github.com/evancohen/smart-mirror.git
Next Step: Install Dependencies