Podcasting is just blogging with a media file attached (video or audio). You have to have each media file attached to a blog post so that each item is in the feed.
Looking at your site, where the sermons are (individually), if those are blog posts, you need to get the URL to each media file and cut and paste that URL into the Podcast Episode box where it says Media URL. Hit Verify and save the post. You will need to do that for each episode (sermon).
Then, once that is done, go to the powerpress settings and in the feeds tab you will see your feed address. This is the address you would give to iTunes, Stitcher and any other directory you would like to be listed in.
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