I've been listening to the Paper Money podcast, which is a podcast about the board game business. It's good too listen to, but I couldn't say that it's been particularly helpful to me as a self-publisher as it seems to focus more on the bigger manufacturers. However, their recent show about trade shows convey lots of essential information about the whole year's calendar's worth of Board Game trade shows, and which ones you should consider attending if you are a designer, a publisher, a buyer, or whatever. Everyone should listen to it, no matter what your particular situation is.
Link to Podcast
http://www.imagigrafx.com/podcast/?p=103
List of Trade Shows with commentary
http://www.imagigrafx.com/game_events.asp
[hyperventilates]