I just installed mine about a month ago. You are probably looking at a USB cord coming straight out of the back of the unit. Then you have a cord that has 3 rca ends and an ipod and usb connection on the other side of it. You plug the rca connectors on that cord into the audio/video inputs on the back of the deck. You then plug the usb connection on the cord to the usb inlet that runs from the back of the deck. After you have done those two things you plug in your ipod. You will then may have to turn the av setting to on and it will read your ipod. Then all controls will be accesible in the AV Source screen where you click on ipod. You can then watch videos from it, search as if you are in i tunes, get all the display information of each song, and even the little circle thing on the ipod with play, next track etc. will be touch screen on the head unit.
Edit: That is how mine it setup anyway. It is really the weirdest thing I've ever seen but it works flawlessly. I stared at that cord for like 10 minutes thinking WTF!!!! And by the way, the video playback if you have a a video ipod, is awesome.