I just finished a semester of working on Radio Theatre with my students. I showed them the Instructional Video from Alien Voices with Leonard Nimoy and John de Lancie from Dramatic Publishing. It shows students practicing the foley and vocal work and then the performance of Alien Voices' Wright Brothers script. They say that they spent 2 weeks rehearsing. Remember that was 2 weeks for 15 minutes of a show.
I forgot that little fact and prepared what ended up being 2 shows of radio scripts - 18 scripts and almost 6 hours in all - and about killed myself trying to get it ready. I had almost 50 students. You don't have many people in a radio script, so I needed lots of scripts to get everyone a part. (We only do one show a year, sometimes 2, so I accept everyone who tries out.)
Things I learned:
1. Be sure everyone has a pencil and a highlighter and that they mark ALL cues the first time and HIGHLIGHT them. Be sure to double check that they did it - don't believe them when they say they did until you see it with your own two eyes. I could have saved a ton of time being sure they truly had marked things, instead of having to go over everything multiple times.
2. As mentioned above, give yourself lots of rehearsal time. Don't underestimate the amount of work needed just because there isn't blocking and they don't have to memorize.
3. One of the things I fought was that my students didn't feel like they were "really acting." They weren't "doing" anything, so it didn't count. It took right up until the end to convince them they were "doing" something and that acting involves your whole body and voice whether you're moving or not.
4. Give plenty of set up time. Mics tend to be fickle creatures and you never know when they'll decide not to co-operate. Always double-check everything.
5. Remind your kids they still have to project. It saves their skin if their mics cut out in the middle of the show!
6. Get them interested by having them listen to I Love Lucy radio shows or Burns and Allen. Our kids loved those. Other favorites that began to help them realize that yes this was acting, were Sorry, Wrong Number and Zero Hour. That last one is creepy and so cool!
7. Resources: The Great American Broadcast by Leonard Maltin for the history of Radio Theatre. There are also lots of websites about old time radio theatre; I especially liked Radio Spirits. They had great compilations of Radio Shows for a reasonable price. My kids love listening to them. www.radiospirits.com is the website where I bought my radio show CD's. They always have a radio crossword puzzle or something on the back of their catalog which is fun for the kids, too.
Another resource we used was Radio Theatre for the Classroom from Contemporary Drama Services. It has some scripts which aren't too impressive, but the beginning has activities to do to teach radio theatre It also has a good sections scattered throughout the book on sound effects to make or find. You will almost certainly need mics at your Foley table to be able to hear the sound effects well enough.