Hello aglick and welcome!
We'll get you sorted. I don't have Nook myself, but others have posted about it. I will do a search, although someone else might have the answers before I return.
Okay, here's a site with the Nook app for download:
http://www.freewarelovers.com/android/app/nook
And here's a quote from Obsessed's excellent "Resources for New Edge and Pocket Edge Owners" thread:
"Nook Android App (Books from Barnes and Noble CAN be read on e-Ink side. Books can be found opening Library App from Home Screen, select Storage (top left pull down), then sdcard/Nook/Content/ Press and hold downloaded book and Add to Library. Use First and Last Name as it appears on the credit card used to purchase the book for Username and Credit Card # for Password."
I did notice on the Barnes and Noble website that the latest Nook app requires Android 2.1 or higher, so if you haven't upgraded to Ermine you may want to do that, or to see if the older versions of the Nook app will run on Dingo (Android 1.6).
Hope this helps! Good luck!