Yes, I use Coloring with Block Crayons, Emphasizing the Primary Colors, 2nd Editionin my classroom. I think it's helpful and I refer to it weekly.
It is 72 pages long. She gives basic exercises for the teacher to do before teaching the techniques, which are wonderful, since you're teaching through imitation here.
She talks concretely about topics such as introducing the materials to the children, starting with a verse, and lots of tips such as how to draw animals (and specifics for foxes, dogs, birds, cats, lions, rabbits, horses, cows, sheep, monkeys, fish, turtles, frogs), how to draw landscapes and skies, buildings, plants, all the things that might trip you up.
The basic technique exercises she covers are bands of color, clouds of color, tone shading, secondary colors, making browns, making a color circle, all color spectrum, drawing ribbons, controlling the width of the stroke, and controlling negative space.
In short, it really gives you a lot of details on all the things you might have questions about! I think it is a good buy. I actually have an extra copy and if someone is interested, just email me off list. I somehow ended up with two.
The CD is helpful. She talks right into the camera, holding the crayons and demonstrating the motions. She also shows beautiful full color drawings that she has done that are pretty inspiring. I think you could live without the CD, though, if you had to, because there are full color plates in the back of her book that also help you to see what's possible. The plates in the book show alphabet examples, such as R for Rumpelstiltskin and B for bee, as well as people you would need for fairy tales (knight, king, queen, farmer and family). She also shows completed full color drawings for "The Frog Prince," "Mother Holle," "The Tortoise and the Hare," and St. Francis and the Wolf of Gubbio.
I got our crayons through A Small Green Footprint, where you can buy the primary colors individually, as many or as few of each one as you want.
P.S. My students went ahead and sewed pouches for their three block crayons, to keep them organized. We used to have three small baskets, one for each color of crayon, but people seemed to want their own to take good care of. I used a piece of Magic Cabin wool felt, cut in half, and then we folded that in half, divided 6 inches by three, measured two inches for each pocket using a ruler and drew lines with chalk, pinned along each line and the edges, put the crayons in while we sewed them (to make sure people sewed pockets that would ultimately fit), and sewed up the chalk lines and the edges. Then I let them sew on snaps to keep the pouches closed when the top flap was down, which they were really excited about because they had only ever sewed on buttons.