Here's how to drag and drop non-DRM downloaded eBooks into the NOOK Reading app for Android:
1. Connect your phone to your PC or Mac to access the folder structure
2. Open the NOOK Folder
3. Open the My Documents Folder
4. Drag any ePub files into the folder
5. Disconnect your phone from PC or Mac
6. Open the NOOK for Android app
7. In the library, filter by "My Files"
You then should be able to open and read any of your files. If you cannot see your files, perform a sync.
At this time, only ePub files are supported. We are evaluating adding support for other types (pdf, pdb, etc).