These are Web sites offering electronic versions of books for free. The majority of the books are older ones due to their copyrights expiring.

Alex Catalogue of Electronic Texts
This is a large collection of American and English works of literature and philosophy. Examples include works by Charles Dickens, Martin Luther King Jr., Plato, William Shakespeare, Adam Smith, Bram Stoker, Mark Twain, Voltaire, and many more. Books are available as txt or pdf.

Baen Books
A number of books from this science fiction and fantsty publisher are free. New titles added every month.

Bartleby.com
This is another huge collection of resources. Includes works of fiction, non-fiction, reference, and poetry. Examples include the Columbia Encyclopedia, Bartlett's Quotations, Roget's Thesaurus, works by Jane Austen, Victor Hugo, Homer, Carl Sandburg, Emily Dickinson, Albert Einstein, and on and on! Book format is html.

Blackmask
Contains full-text of over 13,000 books! Works on biography, fiction, non-fiction, and poetry, many in multiple file formats such as html, pdf, Rocket e-book, and more.

Children's Books Online: The Rosetta Project
Provides hundreds of children's books from the 19th and early 20th centuries. Books may be read online or downloaded, and consist of scanned images of pictures and text. Includes books in other languages.

UC Press E-Books Collection, 1982-2004
This collection includes almost 2,000 books from academic presses on a range of topics, including art, science, history, music, religion, and fiction. Access to the entire collection of electronic books is open to all University of California faculty, staff, and students, while more than 500 of the titles are available to the public.

InkMesh
A search engine for free e-books from more than thirty different sources. Also compares prices of e-books for various e-readers. Search by either title or author.

International Children's Digital Library
Location for many children's books from around the world and in various languages. Books consist of scanned images of the original. Great subject browsing.

Online Books Page, University of Pennsylvania
Archives over 800,000 books and includes special features such as Banned Books, Prize Winners, and Women Writers.

Project Gutenberg
The grandaddy of archived books! Fiction, non-fiction, reference works, musical scores, and much more. The books come in a variety of formats, including plain text, html, and audio.