Wikimedia
Wikipedia: Podcasting
Overview of the Internet broadcasting method. Also contains the origin of podcasting, how the term came to be coined, and other uses of podcasting.
BBC
Bbc News: Podcasts Bring Diy Radio to the Web
This BBC article from 2004 describes the basics of podcasting- "an internet-based radio show which podcasters create, usually in the comfort of their own home".It gives background on the origin of podcasting with MTV host, Adam Curry.
Learn Out Loud
Learn Out loud.com: Introduction to Podcasting
This article gives an introduction to podcasting including ways to listen to a podcast. The site also talks about how podcast directories can be used.