Books online
Project Gutenberg is the oldest producer of free books on the internet. Most of the books are from Western culture and you'll find literature such as novels, poetry, short stories, and drama, but also cookbooks, reference works and issues of periodicals. Most are in English, but there are also large numbers in many other languages. All the works featured are out of copyright in the US, so you won't find anything published after 1923. You can browse by author or title or search if you know what you're looking for. The top 100 lists the most popular. There are currently over 20,000 books available for download.
Google Book search lets you search the full text of books. It works in the same way as web search. Enter a search term and you'll get a list of matching results. Click on a book result and you will be able to see anything from a from a few short extracts to the entire book. If the book is out of copyright you will be able to look through the book from start to finish. Other books will have limited access, but you'll be able to see a few pages or a few snippets surrounding your search term.
The Internet Public Library (IPL) maintains a long list of links to websites that provide online books, from single texts such as A Christmas Carol and Treasure Island to collections based around themes, ie poetry and mythology and to general collections.
The Online Books page lists over 25,000 free books available on the web. The books featured are out of copyright. Search or browse by author or title. The directory is expanding all the time and you can subscribe to an Really Simple Syndication (RSS) feed of new titles added.
Luminarium provides texts from several periods of English Literature. Including Medieval, Renaissance, Seventeenth Century and Restoration and Eighteenth century. Each author has an entry that includes works, biography, criticism, quotations and links.
The British Library's Turning the Pages project allows you to view precious manuscripts from the Library's collections. Using interactive animations, you can turn the pages in a realistic way, zoom in on the images and read or listen to notes explaining each page. Highlights include Sketches by Leonardo, Mozart's Musical Diary and The original Alice. You will need the Shockwave Plug-in to turn the pages. (Alternative versions are available)