These are a few things I did before I got into writing educational curricula.  (Sorry, I don't keep them in stock myself.  You have to go Amazon.com.)

Inside A Freight Train  published in 1993 by Cobblehill Books, a division of E.P. Dutton (now Penguin Books). ISBN 0-525-65099-7  Now out of print.  Used copies are available through amazon.com. 

Musical Instruments Coloring Book, published by Dover Publications in 1995, ISBN 0-486-28785-8

Music Activity Book, published by Dover Publications in 1996, ISBN 0-486-29079-4

Little Tropical Fish Coloring Book, published by Dover Publications in 1994, ISBN 0-486-27951-0

All the coloring books are still in print as far as I know.  The train book is out of print but used copies often pop up on Amazon.

NOTE:  I do not receive any royalties on these coloring books.  You are welcome to order them, but please don't do so in order to generate any income for me.  (18,000 copies of the Musical Instruments Coloring Book were ordered by the San Francisco Symphony Orchestra and I got nothing.)  Dover doesn't give royalties.  At the time I did the artwork I was a "starving artist" so I was grateful for the cash. C'est la vie.