One of my favourite podcasts to listed to is Astronomy Cast. I've even had the fortune to see the recording of some episodes at Dragon*Con and in a Google+ hangout.
Being an astro geek in a former life, astrophotography has been something I've wanted to do for a long time now. I also know it can be an expensive hobby.
Astronomy Cast Episode 239 talks about the gear needed: camera, lenses and tripod. Good discussion on the kinds of equipment needed, plus some very useful links in the show notes. They even talk about using webcams attached to telescopes.
Episode 240 discusses astrophotography techniques. Exposure settings, image stacking, a little bit about detector characteristics, filters.
Good info in both episodes. Next episode is supposed to cover image processing.