What do you need to get started?

Software

By far the most popular, and possibly the easiest, way to take advantage of podcasting is through the use of Apple's iTunes software. The newest version, 5.0, has podcasting capabilities built right in and is available for both Windows and Mac. Using iTunes, you can search through a huge directory of available podcasts, and subscribe to them easily. If a podcast is not listed in the directory, you can add it manually:
Copy the URL for the podcast you would like to subscribe to.
Under the 'Advanced' menu in iTunes, select 'Subscribe to Podcast.' Paste the URL into this window, then click OK.

Another popular program is iPodder, which is available for Windows, Mac and Linux. iPodder is a free, open source program that allows you aggregate podcasts in much the same way iTunes does.

Pubcatcher, which is based on the iPodder software, is a new program distrubuted by public radio stations that makes the process of subscribing to that station's podcasts, and podcasts selected by that station, much easier. So far only a few stations offer Pubcatcher, but more are coming online. Check out KCRW and Vermont Public Radio.

Hardware

Although the most popular device for listening to podcasts is the iPod, any portable MP3 player should work. And if you don't have a portable player, you can listen to podcasts using the MP3 player on your computer. You can use iTunes for Windows and the Mac, or choose from any number of other programs like Winamp, MusicMatch or Windows Media Player.