retropi
I recently started playing around with the raspberry pi 2.
I followed the guide on lifehacker to get this set up.
http=//lifehacker.com/how-to-turn-your-raspberry-pi-into-a-retro-game-console-498561192
The setup is really easy to get going but I did find a couple of commands very helpful. updating
rpi-update will update the raspberry pi firmware
Retropi is based on Debian so apt-get is your tool for general updating. Getting a console
when you are in the games menu hitting f4 on a connected keyboard will open up the console.