What are podcasts?
How to subscribe
Podcasts are radio- and TV-style shows you can download from the Internet. Many think that an IPOD is needed to hear a podcast. This is not true. Audio podcasts can be heard on a mp3 player AND on your computer. Podcasting makes an audio file, typically an MP3 file, available online for downloading via an automatic "feed." You can then hear the podcast whenever you want from your computer or a portable media player.
Podcasts are different from Internet radio stations, which stream live content over the Internet. Podcast episodes are downloaded to your computer so that you can play them when you're not connected to the Internet.
What differentiates a podcast from just being a media file is that you subscribe to podcasts via a RSS feed.
You can subscribe to a podcast by downloading a podcatcher. A podcatcher is software that goes out and finds new episodes of the podcasts you subscribe to and downloads them to your computer. The most widely known podcatcher is iTunes.
You can also use web based aggregators such as MyYahoo to subscribe to podcasts.
Video: Podcasting in Plain English