There are a number of online outlets that offer eBooks in EPUB format - with and without Digital Rights Management (DRM). Some sites offer books for purchase and some have them for free. If the books have DRM, only the ones secured with Adobe® product ACS4 will work with the Reader™ Digital Book.
Some options include:
- Kobo - http://www.kobobooks.com/
- eBooks.com - http://ebooks.com/
- Project Guttenberg - http://www.gutenberg.org/wiki/Main_Page
NOTE: It’s also important to note that the Reader Digital Book also supports personal documents in a variety of formats , including PDF.