Speakaboos brings children stories to life. Some of the things on this site you need a paid membership but there is a lot that is free for teachers to use.
Storyline Online is sponsored by the Screen Actors Guild and has some of Hollywood's top actors and actresses read stories to your students.
One of my favorite children's authors is Robert Munsch. He writes the funniest stories and kids LOVE him. This is his official website and you can listen to the author himself reading his stories. It is great!