Not sure how old this is but Apple offers a free on-demand seminar called The Podcast Recipe: Producing a successful show.

Podcasting is one of the most explosive technologies to hit the Internet. And with literally thousands of podcasts available on Apple iTunes, the need for high-quality production is critical. In this free, on-demand, three-part seminar Apple experts take you behind the scenes to see what it takes to perform a great-sounding podcast, produce a professional show, and promote a podcast to reach as many people as possible.

Obviously slanted towards Apple software but may be useful to some.