I'd not normally point to this, Podcasting 101, too many others are already pointing to it and it is slides from a talk. However, it has some very information packed slides. It is a good introduction to podcasting. Thanks to Jenny Levine and Su Bochenski for such a useful work.
One thing I miss from almost all introductory podcasting talks is any mention of BitTorrent. Many of the tools for downloading podcasts support torrents. Bandwidth usage can become a concern for a popular podcast. You could end up owing your IP service provider a pile of cash. Making your talk available as a torrent solves this problem. There are easy to use, free services where you can make your podcast available using BitTorrent such as Prodigem.