This video is one I came across while searching the web one day for various Photography related info and it was my Introduction to the Atlanta Based Photographer Zack Arias.
Since seeing this video I have spent HOURS on his blog going through Archives and I absolutely Love his Video Critiques of Photographer Web Sites.  If you are beginning/venturing out to include Off Camera flash to your photography, I highly recommend / strongly urge you into checking out his OneLight DVD.