We want to recommend a radio show/website called You Bet Your Garden http://www.whyy.org/91FM/ybyg/index.html . It is broadcast on KCLU 1340am Saturdays at 5am and 1pm, and the website has old shows and a collection of A-Z garden tips. He has great info, he's enthusiastic, and his Philly accent is entertaining.
Because it is based in Philadelphia, some of the info is more applicable to the East Coast, but recent topics have involved composting, re-using potting soil, and seed starting, which should be interesting to beginner and experienced gardeners alike.
cheers,
Sara and Seth