Online Piano Lessons for Kids

Piano Nanny
A website offering free piano lessons. Very helpful and comprehensive tutorial.

Learn Piano Online for Preschoolers
Free downloadable lessons for preschool aged kids. I personally used the lessons here to introduce my daughter to piano playing.

Free Online Piano Lessons
Free lessons for the beginning pianist. Very thorough lessons and has quizzes at the end of each lesson.

Piano for Kids with Dan Delaney
Offers a lot of free lessons for kids. The lessons are easy to understand and it also has some videos you can watch.

Keyboard and Music Theory
Lessons in both piano and keyboard playing. The lessons can be downloaded as a pdf file.