Welcome and congrats on your purchase.
To answer your question. The audio input in the 2007 model is a standard 3.5mm jack (read: headphone plug) located in the arm rest compartment. If all you're looking to do is get sound from the ipod to the stereo then you'll need to buy a 3.5mm-3.5mm cable. Plug one end into the headphone out on your ipod, and the other into the aux input. You can get a cable like that for about $5 at Radio Shack.
Bear in mind that plugging the ipod in this way won't let you control the ipod from the stereo controls (or steering wheel controls as they're just an extension of the stereo). This is simply an audio input, and would work with anything that has a headphone jack (discman, walkman, ipod, random Mp3 player, etc.). If you want to be able to control your ipod through the stereo controls then you'll need a different........ ummm.... module (for lack of a better word) that plugs into the back of the stereo. There are multiple versions available that basically all do the same thing, some aftermarket, and some OEM.
Look
HERE for a list of all of the available options for audio inputs, and ipod integrations methods. Note: All of the ipod integration methods plug into the same port as the audio input in your console. There is a switch box that allows you to plug in the OEM ipod adapter and the console audio input together (Part number is listed in that link), but no one's tested it to see if it works with any of the aftermarket methods.
Hope that helps you out, and wasn't too confusing. Again, welcome and let me know if I can help more.
