An online journal and not-for-profit project dedicated to the exploration of curious and compelling works from the history of art, literature, and ideas. View recent articles:
Google's catalog of books. Contains basic bibliographic information about the book and in many cases a few sentences showing your search term in context. If the book is out of copyright users can view and download the entire book.
Free literature on behavioral and social sciences, education, and health and medicine. Most PDFs can be downloaded for free by the chapter or the entire book.