This is a beautiful site about actors, screen couples, and films. A particularly interesting page is the Alfred Hitchcock one. There is also galleries and a sing-a-long page! Really intesting stuff!
An article about Marni Nixon, perhaps the most famous singing-voice-without-a-face in the history of motion pictures (think of a real-life "Singin' in the Rain" scenario, if you will).
NPR reviews the book "Hitchcock's Music", which examines the celebrated director's relationship to sound. Auditory examples of Bernard Hermann's compositions included.