One of the sites that I frequent, and get monthly e-mails from is Colin Smith's PhotoshopCAFE (
www.photoshopcafe.com).
Colin authors a number of books, teaches at Photshop World and also produces a number of videos on Photoshop, Flash and photography.
I have the videos he did on "Perfect Exposure", which is a great complement to the book "Understanding Exposure", both of which I recommend.
Just got an e-mail that he's just released a new series called "Perfect Composition". There are (lots of) times when I struggle getting good composition, so it's something that I'm looking at getting.
http://www.photoshopcafe.com/video/p...omposition.htm