The best HP podcast
Is the one by the Unspoiled netowk IMO. http://www.unspoiledpodcast.com/category/literature/harry-potter/
The host Natasha found someone completely unspoiled and her read all the books and podcast about them. All she knew when they started was that they were about Harry Potter and that he was a wizard and went to a school :D
It's so much fun, though they're almost at the end now.
There is no such thing as too much time