Build a Jukebox from a Raspberry Pi

A Raspberry Pi (The model B, B+, or 2 will work)
A power cable for the Pi, ethernet cable (or Wi-Fi card), SD card, and a keyboard for setup
A touch screen (we used this one, the PiTFT from Adafruit)
A home server or computer with MP3 files on it
A stereo and speakers to connect your jukebox to
A case (optional, but people will be touching it, so you should get it in something. The new official case will work great)

See the full instructions at LifeHacker