Had a look at the podcast directories - again, lots of American content, so I don't know how often I'd actually use those to look for things to subscribe to. Mostly I find podcasts on the sites I'm already interested in anyway, or find out about them by word of mouth. National Radio has podcasts from their various shows and I've put a feed on my Bloglines site to their regular movie review guy, who is very good. They also archive many of their interviews.
http://www.radionz.co.nz/audio is where you will find all their feeds.
What will be more helpful in the long run is the tutorial material on how to create your own podcast - I can see this being good for book launches, Heritage Week - that kind of thing - especially now our new PA system allows us to digitally record events.