It looks the instructions I needed below for wireless setup were at http://wiki.debian.org/rt2870sta
I did have to blacklist the rt2800usb driver by putting "blacklist rt2800usb" in a new file at /etc/modprobe.d/rt2800usb.conf
Add a "non-free" component to /etc/apt/sources.list, for example:
# Debian Squeeze/6.0
deb http://ftp.us.debian.org/debian squeeze main contrib non-free
Update the list of available packages and install the firmware-ralink and wireless-tools packages:
aptitude install firmware-ralink wireless-tools
3. If not already performed, connect the device to your system.
The necessary kernel module should be automatically loaded. If necessary, it can be manually loaded via:
Verify your device has an available interface:
Raise the interface to activate the radio, for example:
ifconfig wlan0 up
Configure your wireless interface as appropriate.