WatchKnow.org looks like a great place to search for educational videos suitable for children from 3 to 18.
A large range of subjects are covered including, English Language, Literature, Maths, Science, History and the Arts. You can search by age and by category and there is an option to limit the results to 'school accessible' content only - so the videos you find can be accessed in schools where content from sites like Youtube or Google Video can often be blocked.
WatchKnow was launched last year (October 2009) by the co-founder of Wikipedia, Larry Sanger who describes it as "YouTube meets Wikipedia".
The site aims to make finding high quality educational videos easy to find. So instead of needing to visit lots of different sites, like YouTube, Schooltube, Google Video, Teachertube, National Geographic, etc. and searching through educational and non educational videos you can visit just one site and search through only educationally relevant resources.
The site invites students, parents, teachers, librarians, and everyone interested in the education of children to use and help develop the resource. (Sign up for an account to get invloved.)
I did a quick search for children's book ages 4-6 and found a large number of results; I particularly liked... Michael Rosen Performs 'We're Going On A Bear Hunt' and The Velveteen Rabbit by Margery Williams.
Take a look.
:)
