First make sure you have iTunes installed. You can download it for free from here:
http://www.apple.com/itunes/download/
Once iTunes is installed, go to the class' main page in Catalyst and click the “Subscribe to Podcast” link. iTunes will automatically launch and add the class' podcast to your list of subscribed podcasts.
Note that when first subscribing to a podcast, older episodes are not downloaded automatically, so you need to click the “Get” button for each one you wish to see. However, you can set Preferences so that all future episodes are automatically downloaded.
Podcasts appear in the Podcasts source and in the Library. Click the Podcasts icon to see all your podcasts. Recent podcast episodes that have not been downloaded to iTunes appear dimmed. To download a recent episode, click the “Get” button next to the episode.

Illustration
1: Podcast sources with "Get" buttons
Playback is controllable with the Play/Pause/Previous/Next buttons just like with any other file in iTunes. The podcasts will contain audio, video, or PDF content. Audio and video are playable within iTunes, but PDF files will open in a separate program.
Viewing PDF files requires a PDF reader (such as Adobe Acrobat). If you do not have one installed, you may download one freely at: http://www.adobe.com/products/acrobat/readstep2.html
(by default this download comes bundled with unnecessary extra software, so uncheck the “Adobe Yahoo! Toolbar” and “Adobe Photoshop® Album Starter” checkboxes if you wish to prevent this)
Use the Podcasts pane to set how often iTunes
checks for episodes and what to do with them.
Click the Podcasts tab to tell iTunes how often to check for episodes and what to do when it finds them. To set how often to check, choose an interval from the Check for new episodes pop-up menu (drop-down in Windows). You can choose Every hour, Every day, Every week, or Manually.
To set what iTunes does when it finds episodes, choose an action from the When new episodes are available pop-up menu. You can choose Download all, Download the most recent one, or Do nothing (you can manually download episodes by clicking the Get button next to an episode when you select Podcasts in the iTunes Source list).
You can make iTunes do a little housekeeping—or not—by choosing how many episodes you want iTunes to keep from the Keep pop-up menu. You can choose All episodes, All unplayed episodes, Most recent episode, Last 2 episodes, Last 3 episodes, Last 4 episodes, Last 5 episodes, or Last 10 episodes. If you need to reconfigure which podcasts get copied to your iPod, click the "iPod Preferences" button to go to the iPod pane in iTunes preferences.
Click OK to save your changes or click another tab to set other preferences.
If you have an iPod, select one of the two "Automatically" radio buttons to have iTunes automatically copy all podcasts, or selected podcasts, to your iPod whenever you connect it. If you select the "Do not update Podcasts" radio button, you can still manually copy podcasts to your iPod. Use the Update pop-up menu (drop-down in Windows) to choose which podcast episodes to copy to your iPod; you can choose All episodes, Only checked episodes, Only most recent episode, or Only unplayed episodes.

Illustration
3: Open this preferences page by selecting “Preferences...”
from the “Edit” menu and clicking on the “Podcasts”
tab.
Portions of this document are from the Apple support site and the iTunes help document.
1/30/2006 by Jacob Klint (jklint@merage.uci.edu)