To learn more about 1930s radio, you might want to take a look at this book, which has been instrumental in researching for this website: Dunning, John. On the Air: The Encyclopedia of Old-Time Radio. New York: Oxford University Press, 1998.
Many images in this site can be found in Rhoads, B. Eric. Blast from the Past: A Pictorial History of Radio's First 75 Years. West Palm Beach, FL: Streamline Publishing, Inc., 1996.
Perhaps the best related site on the web is Old-Time
Radio. This comprehensive site provides much information including
programming guides, audio files, and tape-trading opportunities.