Sideloading means transferring files from your personal computer to your NOOK over the USB cable.
If your personal computer is a Mac, you will need to install a free software program, Android File Transfer (AFT), on your computer before you can transfer files to and from your NOOK.
AFT is available here: https://www.android.com/filetransfer/.
If your computer is a PC, it will automatically detect your NOOK and install the software drivers it needs, if they are not already installed.
To sideload content:
1. Connect your NOOK’s USB cable to a USB port on your computer.
2. Connect the other end of the cable to your NOOK’s Charger/Accessory Port on the top edge of your NOOK.
3. On your NOOK, swipe down from the top edge of the display to open the Notifications menu and tap on “USB for charging”.
4. Select “Transfer files (MTP)”.
5. Use the File Explorer on your computer to access the storage on your NOOK.
Once you have connected your NOOK to your computer, you will be able to access your NOOK’s storage as though it were another drive connected to your computer.
6. Select the files you want to transfer from your computer, then drag and drop them from your computer to the storage of your NOOK.
NOTE: You can view PDF documents using the Nook software by copying the PDF file from your computer to the Nook/copy folder location in internal storage.
7. Once you finish sideloading the files you want to transfer, disconnect your NOOK from your computer by using your computer’s file system to eject your NOOK as if you are ejecting a disk.
8. Use your NOOK’s File Manager app to view files copied to your NOOK’s storage.
To view the amount of storage available on your NOOK, open the Settings app, and select “Storage & USB”.
You can also transfer files to your NOOK using Dropbox or any other file-sharing app you have installed on your NOOK.