I'm very behind on my podcasts and have only just listened to The National Archives podcast from 30 November 2011 entitled "Making Geographical Sense of the Census". Its focus is on maps and boundaries. Quite a few people have commented that they have had difficulty establishing an "official" boundary for their place, and this podcast will shed some light on the futility of trying to come up with a definitive boundary!
You can grab the podcast from http://www.nationalarchives.gov.uk/rss/podcasts.xml, or via iTunes/your usual RSS or podcast service. The sound quality of this one is unfortunately a bit erratic but the content is worth it. I'll be listening to it again to make sure I've picked up on the all the resources they mentioned.