From an OverDrive Announcement:
OverDrive [is announcing] the release of the free OverDrive Media Console app for NOOK, making it even easier for users to borrow eBooks and audiobooks from libraries and schools. With the new OverDrive app, users of NOOK HD, NOOK HD+, NOOK Tablet and NOOK Color can wirelessly borrow eBooks and MP3 audiobooks from the library [sideloading files is no longer needed].
Users can visit the NOOK Store to install the free OverDrive Media Console app. The app enables users to locate a library or school nearby, browse or search their eBook collection and, after entering a valid library card or school ID, check out and download the title for a lending period of one to three weeks (depending on the library or school’s policies). At the end of the lending period, the title simply expires.
Direct to App (via NOOK Download Store)
Additional Info (via OverDrive’s Digital Library Blog)
UPDATE (10/3): 3M Cloud Library Releases App for NOOK, Wireless Downloads Now Available