All the things I know about obtaining the best possible sound quality using Garageband. Deals with popular question: "how do I eliminate background noise" (spoiler: the solution is probably not what you want to hear.) What are your feelings when it comes to sound quality?
Tutorial suitable for users running Garageband versions prior to Garageband X (came out with Mavericks) that has stripped out podcasts as a function. X's interface is completely different, sorry.