If you are using a BrailleNote Touch device, here are some ways to find, download and start reading your books is to:
Dolphin Easy Reader:
Braille Note
June 2, 2014
If you are using a new BrailleNote Touch device, the easiest way is to use Go Read. Learn more here.
Otherwise, you'll need to use removable media such as a flash drive or memory card to copy books to a BrailleNote.