There is a good book in Australia !!!!
The Arts in Early Childhood
by Susan Wright.
Published by Prentice Hall Australia 1991.
ISBN number.. 0 7248 1188 5
Prentice Hall are a division of Simpon and Schuster if that is any
Prentice Hall give a US address as Englewood Cliffs New Jersey
Just stay away from colouring in and cutting out pre drawn images
Let them draw, paint, clay and play dough sculpt and make at their
own level.. you do not "teach" art at this lever rather,
encourage arts expression. Good luck in your new venture.