These instructions were excerpted from the Barnes & Noble Website and edited for your information.
You can sideload eBooks that are not protected by DRM into your Nook. None of Zeece Lugo’s books is DRM protected.
You can transfer EPUB files, PDFs, and Microsoft Office files from your personal computer to your NOOK. Mobi files must be converted into Epub format before sideloading into Nook.
To transfer files:
Step 1: Using the custom microUSB cable provided with your NOOK, connect your NOOK to your personal computer.
Step 2: Your NOOK will appear as a new disk drive called MyNOOK or NOOK on your personal computer. Drag the files you want to transfer to the MyNOOK drive.
NOTE: If you connect your NOOK to a Windows PC, the PC might display a dialog box asking if you want to install a driver for NOOK. Click Cancel to close this dialog box. You do not need to install a special driver to transfer files to your NOOK.
On a Mac, you should install the Nook Connect drivers the first time you connect your device, so that you can easily see the files on your NOOK.
Step 3: To organize the files, open the MyNOOK drive. You will see several folders on your NOOK. Drag & drop your book file from the computer’s download directory into the MyNook’s “Books” folder.
Step 4: When you have finished copying your files, eject the MyNOOK drive from your personal computer to safely unmount the NOOK file system. (The specifics differ by operating system, but generally involve right-clicking the NOOK icon and choosing Eject.)
Step 5: Disconnect the microUSB cable.