The podcast directory in the iTunes Store allows you to find and subscribe to new podcasts.
 
To subscribe to a podcast, click Subscribe on the page for that podcast. When you subscribe to a podcast, iTunes will automatically check each day for new episodes.
 
You can also stream an individual episode from the iTunes Store by clicking its episode number in the episode list.
 
You can manage your podcast subscriptions and play the episodes you have downloaded in the Podcasts section of your iTunes library.