We've just published our second podcast episode and some things are getting easier to do and understand. Something that had a great impact on me was going from a USB headset microphone to a "real" microphone and hearing the dramatic improvement in the sound quality.
We record mostly with a Powerbook and a
FastTrack USB device attached. The FastTrack has a XLR-input which is the large, round, connection that regular mics have. Then we use a
mic from Radioshack which is unidirectional, meaning it only picks up sound coming from one direction, i.e. straight into it. That means it picks up a lot less of the surrounding sound. It also means it's more to think about for whoever holds the mic since it has to point straight into the mouth of the person who speaks.
This is certainly not high-end equipment, but to us it produces amazing sound quality. All-in-all we spent around 700 Dirhams on the podcasting equipment so it wasn't very costly.