I’ve used PBS Kids for a long time but have just discovered: http://www.sproutonline.com/sprout/home/ which is part of the PBS website.
Your children will love the games. Choose the Type of game option to decide which skills you want to work on – Memory, Fine Motor skills, Literacy building, Problem solving, etc.
Don’t forget to check out the Videos & Music section where you can download music and podcasts.
It has some great resources for both teachers and parents. Enjoy!