World eBook Fair has offered free downloads of books from July 4 to August 4 since 2006. This fair is sponsored by the World Public Library. The World Public Library has classic books in childrens' and science fiction plus many government publications. There is a selection of audio books. These are both related and linked to Project Gutenberg. Gutenberg promotes free ebooks and has a variety. You can RSS feed it to your homepage to get daily updates on newly added books.
The Best Places to Get Free Books led to Daily Lit which allows one to subscribe to books in daily/weekly installments on their RSS feed. I subscribed to Common Sense by Thomas Paine, as it is one of the ALA Library selections. It is in 24 installments. I would go for 48 to get fewer words per day - more like a daily words of wisdom.