If you are interested in the history of comics you will be interested in looking into the important precursors of comics, namely certain pulp figures. Of especial interest for me is the figure of Doc Savage. His place in the evolution of comics, heroes, and general iconography is clear and vital.
Here is a decent if sparse (on information) three part mini-documentary discussing Doc Savage.
It could be better described as an extended bibliography for all things Doc Savage more than a documentary, but there are certainly worse ways to spend half an hour.