i think the best training is to go out and do it even if you don't know much. No one ever really taught me. I usually get inspired by just watching those behind the scene DVD features they have.
I've found books more helpful (and less expensive) than videos. Another suggestion that builds on jvdark's is to watchd DVDs with audio set to director commentary tracks. Some commentaries not helpful or interesting, I find that the good ones have more info than I can readily absorb.