As far as podcasts go that is going to differ from person to person. There is one I listen to that is 2 hours long and since it's a radio show I get a new episode 6 times a week. The content of it won't interest you unless you align with my political beliefs. That type of podcast seems to keep my attention more than one only updated once a week. I have a RSS feeder on my phone and it keeps all my podcasts up to date.
A podcast you might like is upgrd.com by some fellow FTers. I couldn't find them in the podcast directory in my RSS feeder, but I manually added the feed and it keeps me up to date just fine. I think it's weekly and is around 30 minutes.