Carson McComas has posted 20 good ideas for podcasters to keep in mind. He wrote this in February, but it somehow slipped through my aggregator until now. While a lot of this is subjective in nature, there's a lot of good things to consider. Twenty is a lot of points and my hat is off to Carson for the work. My top 2 favourites are:
Don't take yourself seriously: I absolutely agree with that. While it's important to be professional, there's no need to be pompous. Leaders all over the world know that the smartest person in the room is never the person at the front talking. The same is true of podcasting - you may be the person with the show, but there are many people out there who are more knowlegeable about the topic you're speaking on.
Be chunky: This refers to breaking the show up into segments separated by sound bumpers or other diversions. If your show is over 15 minutes long, I would recommend this. Take a look at any main stream media show you wish and you'll see that they rarely do segments over 10 minutes. Part of this is to provide space for commercials, yes, but the timing is also based on years of research.
Hmm...this list is ringing a bell now, but a search of Biz Podcasting doesn't turn up anything.