Once your site is up and running, you will be able to submit your mixes directly to the iTunes store to be sent out as podcasts.
You MUST have at least one mix loaded to your site to open a podcast account.
Check the information on setting up your account here.
Once you have the account, submit your podcast to the iTunes store following these instructions. Your feed address is simply your website with this added on the end:
/feed/podcast/
e.g http://www.yoursitename.com/feed/podcast
Do not worry about messing anything up, all you need to be sure on is naming the podcast correct.. everything else can be amended along the way.