Tumblebooks - free eBooks, lessons and activities - http://asp.tumblebooks.com/library/asp/home_tumblebooks.asp
Project Gutenberg – free eBooks: http://www.gutenberg.org/
Library of Congress - frree eBooks: http://read.gov/books/?123
Feedbooks: thousands of free public domain eBooks: http://www.feedbooks.com/publicdomain
Google Book Project: http://books.google.com/
International Children’s Digital Library (children’s books from many countries,in many languages): http://www.childrenslibrary.org/
Oxford Owl eBooks: http://www.oxfordowl.co.uk/findbook
Free classic books: http://www.ebooks-for-all.com/bookmarks/list/onecat/Free-ebooks+Chidren-s-books/0.html
Article: 162 Sites for Free Children's Books Online: http://www.techsupportalert.com/free-books-children
Books Should be Free - classic digital audiobooks and eBooks - http://www.booksshouldbefree.com/
Mightybooks - wonderful flash animated audiobooks (the art & music section is great!): http://www.mightybook.com/
Kids AudioBooks - http://www.kidsaudiobooks.co.uk/complete_list.htm
Lit2Go - Audiobooks organized by grade level: http://etc.usf.edu/lit2go/readability/flesch_kincaid_grade_level/
StoryNory - free audio stories (one new each week) - http://storynory.com/
Lots of children's authors have some audio stories on their websites - look up your favorites! Here are a couple of examples:
Little Critter (Mercer Mayer) - http://www.littlecritter.com/
Robert Munch -http://robertmunsch.com/books
TeachingBooks (many authors)- http://www.teachingbooks.net/
Article: 47 Places for Free Audiobooks: http://www.techsupportalert.com/free-audio-books-children