The podcasting techniques work for video as well as for audio. A wide-spread use is the "radio show" format (you know, some music as an intro, a show name, a show host, a weekly topic, sponsors, etc), and in fact many existing radio shows distribute as podcasts over the Internet as well.
The main tool required is an audio or video editing program that lets you edit long files (30 minutes or more), create multiple tracks, etc. You want something better than the built in Sound Recorder application because you want to record podcasts by section.
If you pay attention to the typical professional radio show you'll see they record and edit it in segments. This makes it easier to record and edit, because otherwise you'd have be performing the show straight through, and if you made a mistake halfway through you'd have to re-record the whole thing. By recording and editing in segments the work is a lot easier, because you only have to re-record a few minutes at a time.
[Wikipedia] Gives an overview of podcasting's use, and history.
[About.COM and About.COM] A tutorial on how to create a podcast. They show that a podcast is simply a specially formatted RSS file. They recommend Audacity as the audio editor, but almost any audio editor will do the trick. [podcasting news] has a similar tutorial.
[engadget] Shows a mac-optimized way to recieve podcasts or to create them. [podcast411] has a similar tutorial.
[audioblog.com] Service to help bloggers insert audio or video into their blogs.
[AndyCarvin] A tutorial on using a mobile phone to create a podcast.
[The Otter Group] A few hints to creating a "high quality podcast".
[acidplanet] Shows how to use the ACID Music Studio to create podcasts.
[audio activism] Shows how to configure Word Press to support podcasting.
