The lecture below was given by curator, Timothy Anglin Burgard on Sept 7, 2013 during the De Young exhibition, Richard Diebenkorn: The Berkeley Years, 1953—1966. Titled Richard Diebenkorn: Known and Unknown, it gives a wonderful overview of Diebenkorn's work. Start at 7:00 minutes.
I also recommend this 30 minute lecture given on the same day about artists influencing other artists. Presented by curator Janet Bishop, it is titled Painters Looking at Paintings: Henri Matisse, Richard Diebenkorn, Wayne Thiebaud, and Robert Bechtle.
And here is a short clip in which Richard Diebenkorn discusses the practice of making art and the relevance of landscape.