This set of eBooks covers many topics, but is particularly strong in literature, religion and history. Many books in the Bloom's series are available, as well the texts of sacred works. This site also has many career guides.
Springer's eBooks provides electronic full-text copies of over 12,000 published print materials, such as reference and scholarly books. These books are available to download in PDF format, with no DRM.
The Salem Press site allows you to access online certain reference books from the library's collection. Some of the titles included are Magill's Medical Guide, The Encyclopedia of American Immigration, Great Events from History, Careers in..., Critical Survey..., and The Encyclopedia of Global Warming.