Hi, Jim,
I don't know anything about DRM'ed ebooks from BN, but I download ebooks (pdf ebook and epub format) from my public library's OverDrive service all the time. Here's how:
Step one: download and install Adobe Digital Editions software from
http://www.adobe.com/products/digitaleditions/
Step two: follow Adobe's instructions to authorize your computer
Step three: With ADE running, download the ebook from your public library's OverDrive website using the "open" rather than "save" option in the popup window. The ebook will download into the "borrowed" folder of ADE.
Step four: connect the Augen to the computer's USB port. It should be automatically recognized and authorized and show up as a device in the left hand panel of ADE. If your ebook is a pdf, just drag and drop it into the Augen; if it's an epub, you'll have to strip the DRM, and transfer the book through Calibre, because there's a bug in Augen firmware in how it handles epubs transferred through ADE.