An absolutely lovely resource I have recently discovered is The Picture Desk. It contains both the Art Archive and the Kobal Collection. The latter is an enormous collection of stunning photograhs from every era of Hollywood. The black-and-whites are particularly staggering. I came across them in a recent issue of American Heritage Magazine which had a picture of the original King Kong on the cover.

I seriously recommend that you look around their site and see if they have anything you might be interested in. A note: they will not license their work for commercials or ad-related projects. Educational or documetary is more their line. Their customer service is stellar, too.