Q: Before purchasing my AirPort Express, I figured that once I had it set up, I would be able to not only stream music from iTunes on my notebook to my stereo, but would also be able to plug my iPod into the USB port and sync it with with my notebook wirelessly. Is this possible or was I a little too hopeful?
A: Yes, you were a bit too hopeful.
The USB port on the AirPort Express is designed for you to connect a printer and print from any computer on your network. You can, however, use it for one thing with your iPod: you can charge your iPod by plugging its USB cable into that port.
But you cannot sync your music from iTunes via the AirPort Express.