Critch,

A really good movie to watch if you want to learn more about howling would be "Calling all Coyotes with Randy Anderson". It is about a 2 hour movie, he goes over how to make about any type of howl there is. It s a good movie and i picked up more than a few tips off of there. I know you can get it from cabelas and probably about any other sporting goods store.

Good luck
Tom