Free Printable Music Theory Practice Sheets
http://www.makingmusicfun.net/htm/printit_notename.htm
Online Interactive Music Lessons
http://www.childrensmusicworkshop.com/musictheory/index.html
Music Theory Games & Activities
http://www.wartgames.com/themes/music/musictheory.html
San Francisco Symphony Kids Music Lab
http://www.sfskids.org/templates/musicLabF.asp?pageid=23