Podcasting is the creation and dissemination of MP3 files (known as podcasts) for people to listen to on their computer or on a portable MP3 player. These MP3 files are not the usual set of song files that many people download or copy from their CDs. These files are talk shows, music shows, recordings of talks and speeches and maybe people reading the texts of books -- the genre has a wide variety of formats but the most common at this point is podcasts similar to a radio show (talk, music, variety) that can be played on demand. The name is a derivative of the one for Apple's iPod.
Podcasts covering a specific topic will not go here. They''ll get submitted to the appropriate area of ODP for that topic.

Example: A podcast about scuba diving would likely find a home in Recreation: Outdoors: Scuba Diving or a subcategory, for example. A podcast about diving in Hawaii may end up in Regional: North America: United States: Hawaii: Oahu: Recreation and Sports: Scuba Diving as well as the Recreation/ category.

mailing lists or forums covering podcasting.
Relatively comprehensive directories of podcasts. Directories = categorized, hopefully annotated collections of sites. It's a bonus if these sites are searchable too.
Link collections without a lot of structure are a poor candidate for listing here.
"how to" type of content as well as troubleshooting ideas.
Contains podcasts with are religious in focus.