Oddly enough, out of the 78 new cars I've sold this year, not a single person had a PDA or smartphone that I had to pair with their SYNC equipped vehicle.
Normally all I do is activate their bluetooth. Then I activate the add device sequence on the SYNC equipped vehicle. The phone finds it and then I open the SYNC pairing on their cell phone menu. After that you enter the PIN displayed on the HU of the SYNC equipped vehicle into the cell phone SYNC menu and it should automatically pair the device. From there SYNC will probably tell you to be safe and all that crap. It will ask if you want to download the phonebook. After that you're pretty much done.