FL Studio is without doubt the easiest composing software especially for beginners... the Piano Roll is really quick and easy to get ideas down. http://www.image-line.com/flstudio/
I stumbled upon this site by accident, and am very glad I did. As a bumbling untrained music teacher, I like your hints about how to teach - although I
Auld Lang Syne sheet music for New Year's Eve & other gatherings! Piano arrangements, guitar tabs, & lead sheets with chords in many keys, for all singers.