Congratulations to Cicadaman & co. for getting Froyo running on the Nook Color! Visit the nook Color portal!
See Rooting new hardware FIRST if you have a nook original with a 1003* serial# or above.
Adb
From nookDevs
Android Debug Bridge (adb) is a versatile tool lets you manage the state of an emulator instance or Android-powered device. Full documentation and list of commands available in adb can be found here.
For commands that list adb, navigate to /tools from the Android SDK with a command terminal.
Also, see ADB Over USB for detailed instructions.