Memoware.com - Has thousands of documents (databases, literature, maps, technical references, lists, etc.) for PDA users.

ManyBooks - Has free ebooks, pre-formatted for reading on your PDA - eReader, PDF, Plucker, iSilo, Doc, or zTXT eBooks for your Palm, Pocket PC, Zaurus or Rocketbook!

Amazon eBooks - Free and discount eBooks in various formats for downloading.

MobiPocket.com - Has software and eBooks for PDA users.

Project Gutenberg - Contains many free e-texts of books published pre-1923. These include the classics from authors like Shakespeare, Poe, and Dante.

PocketPC eBooks Watch - A site with news and links on ebooks and ebook technology for Pocket PCs.

Qvadis Bookshelf interlibrary - Contains links to eBook collections in various categories.

Beamable.com - Has comics and  graphical novels for Palm or Pocket PCs with free previews.

On-line Books Page - An index that includes more than 14,000 English works in various formats.

University of Virginia's e-books - Has 1,800 publicly-available e-books including classic British and American fiction, major authors, children's literature, the Bible, Shakespeare, American history, African-American documents, and much more. For MS READER and Palm Devices.