I accomplished this all via personal cold out reach to Podcasters sharing my new website with them. Many of them responded back to me with kind words of encouragement for PodDiscover and submitted their RSS feed.
Many of the Podcasters also have been submitting trailers (short 1 to 3 minute audio file which is a basic overview of what the show is). This is a big deal as the trailers are, in my opinion, going to be an integral part of the site. Since this website is all about finding new Podcasts to listen to, being able to listen to a short trailer really helps potential subscribers decide whether or not they want to start listening to your Podcast.