Its time to learn the recorder! Here is an excellent website to get your children started. (Thank you, Suzy!)
http://www.squeakysrecorderplayhouse.com/recordermaster.htm
Practice holding the recorder properly and check out the fingering chart.
Here is another fun resource. Let’s Learn Music Books 1, 2, and 3. These introduce reading music quite simply. The first book is especially fun for younger children and incorporates coloring and dot to dots.