Whoops,
Taken direct from Itunes pages they cover
This document covers the following topics:
Submission and Feedback Processes
Creating Your Feed and the Importance of Good Metadata
Understanding the iTunes Client and the iTunes Store
Testing Your Feed
Submitting Your Podcast to the iTunes Store
Submission Errors and Duplicate Feeds
The Submission Queue
Linking to Your Podcast
Adding Episodes
Troubleshooting Your Feed
Removing or Blocking Your Feed
Changing Your Feed URL
Being Featured on the iTunes Store Podcast Page
Tracking Usage
Automatic Unsubscribe
via Apple – iTunes – What’s on iTunes? – Podcasts – Technical Specification.