Problems Backing Up iPod

I have had this trouble before, restarting the computer and the ipod worked the last time, but this time, it didn't. Ive tried updating itunes, it backed up more than usual (over half way across the status bar in itunes) then froze. I have tried to back it up many times restarting the computer and ipod all times and it didnt work. It will load not even a quarter across the status bar. I am trying to back up before I install ios 6.0.1. Please help!!! Thanks!