At the bottom of the list of download links on the right side of the page, click Subscribe in iTunes.
Depending on your OS and web browser, this may open a confirmation window asking to open iTunes.
When iTunes has opened, it will ask for login information. Use the email address and password that you use to log into EM:RAP. They are case-sensitive.
iTunes will fetch new episodes automatically. You can sync downloaded episodes to your mobile devices.
Mel explains how to subscribe to EM:RAP in iTunes.