Google Book Search books are printable if switched to plain text, or page by page by right clicking on image of page(HTML mode only). *Switch to HTML(bottom of main Google Books Menu page) . **Click on the download button at link(upper right on sidebar) to download entire text in PDF.
*(10/10)This has been disabled. Hopefully the HTML button will come back. Books listed here are still linked in HTML. I have been able to change the end of the web address by hand from Text to HTML.
**(12/10)Google Books removed the PDF download button on the overview "About" book pages! To access a download, click on any page of the book to find the PDF download button in the upper right corner.
Project Gutenberg books are downloadable, fully printable, and readable online in plain text and illustrated(HTML version - regular web page). See download tips.
Internet Archives indexes several free book resources, has an excellent search engine, fully printable books, and an online flip-book reader with an audio reader. Readable online as plain text or as HTML(like a regular web page).
Rosetta Project groups vintage illustrated children's books by reading level, easy to read format, and has an audio reader. Not in public domain per their format. Read only, books downloadable for small fee.
International Children's Library illustrated contemporary children's books for reading online only. Audio reader available. Not in public domain.
Christian Ethereal Classics Library downloadable Christian books, readable online in HTML(like a regular web page).
19th Century School Books A collection of 140 school books. Printing pages is allowed; however downloads of the entire book are by permission only.
Munseys Hundreds of free books released under the creative commons. Free to share by linking. Various downloads, pdf available.Virtual Homeschool Library