How can I hookup both a usb hard drive and a usb printer to the airport extreme usb port?
How to hook up a hard drive and a printer to airport extreme usb port?
You need a powered USB hub.
The Printer and hard drive connect to the hub. The hub connects to the USB port on the AirPort Extreme.
Example:
http://www.amazon.com/Dynex-Port-USB-2-0-Powered/dp/B001G5ACII
Your local computer / electronics superstore will have just what you need.