Podcasting and Old Time Radio

As I prepare for podcasting, I am reviewing old time radio shows with new ears. What makes a good radio show? How are the transitions done? How short are the items? What sound effects do they use?

Now I've found a wealth of material at Old Time Radio. 12,000 shows! From Fibbie McGee and Molly to Our Miss Brooks and Red Skelton. These require Real Player and will play in the background, while you do other things! That's 18,000 hours of listening at 30 minutes a show!!