Here are some links that might be of interest to you in your radio drama needs.

http://www.audiotheater.com
http://www.audiodramatalk.com
http://cybersleuth-kids.com

Great Northern Audio Theatre does light-hearted and comic original stories.
http://www.greatnorthernaudio.com/

Here is a rare film on early radio drama 1938.
http://www.archive.org/details/Backofth1938

http://www/iceboxradio.org
The Icebox Radio Theater exists as an education and charitable and literary group dedicated to the study, practice and production of radio theater in Minnesota.

http://www.upstagereview.org/radiodramasites.html
Theatre on a Shoestring - For Quality Theatre on a Tight Budget.

Here is a website dedicated to Elizabeth Mumbet Freeman. We offer a script on her life and you can learn more here http://mumbet.com

Streaming Music On-Line http://www.dizzler.com

http://www.freeeslmaterials.com/drama.html