Before going to the upcoming exhibition at the Denver Museum of Art, you may want to check out the biography Van Gogh: The Life by Steven Naifeh and Gregory White Smith. The exhibition at the DAM is called Becoming Van Gogh and runs October 21, 2012 to January 20, 2013.
At the Clyfford Still Museum the exhibition Vincent / Clyffordis on view through January 20, 2013 and explores the connections between Van Gogh and Still.