Podcast - reference

Definition from Wikipedia
http://en.wikipedia.org/wiki/Podcast

Yahoo Podcast
Yahoo Podcasts is intended to enable people to easily search podcasts through keywords, categories or user-generated topic tags. The beta site also highlights podcasts of note, those that are particularly popular and user recommendations and ratings. Yahoo plans to eventually offer tools that will enable people to create their own podcasts.

Examples
http://podcasts.yahoo.com/

Step by step, create your own podcast
http://reviews.cnet.com/