Recently I bought a book of Taro Gomi, a Japanese man. It is a book about drawing with children and it is amazing!! The book is actually so simple, but so inspiring. It triggers the fantasy of children, for instance, he has drawn a boat without sails and then the children have to draw and colour the sails themselves. Or you see a blank page and he asks the children to draw the invisible man... but how do you do that? I think grown-ups would draw nothing, but I think children have all kinds of ideas about that.
Anyways I found some photos of him on the site of Chronicle Books, they publish a lot of his books in America, www.chroniclebooks.com.
Just buy one of his books and enjoy!