Have you thought of listening to podcasts as well? Marshall Goldsmith's are at http://coachm.hipcast.com/rss/marshall_goldsmith.xml

These could also be useful to your entrepreneur side:

David Maister http://feeds.feedburner.com/DavidMaistersBusinessMasterclass

Negotiation Tip of The Week http://feeds.feedburner.com/ottergroup/negotiationtip