How do I connect my ipod touch 32GB to my BMW?

I just bought a 2008 bmw 3 series. I tried to connect my ipod through the usb cable and an aux cable that I bought at best buy but it does not work. The idrive shows that the usb device is not supported. What do I do?How do I connect my ipod touch 32GB to my BMW?I'll wager you'll need iPod's cable. Universal-type cables won't work.