How do you sync a ipod touch to a ford fusion?

I have an Ipod touch 3g with 4.0 software, and a ford fusion 2010. I plugged my usb into the compartment but what do I do next? when I access my ipod in the music it says accessory connected.How do you sync a ipod touch to a ford fusion?Assuming you having sync you would press the sync button on your steering wheel and say usb then say what ever music you would like it to play, or once it is connected you can change though the songs with the next track button