There are a lot of audio editing software choices but I'm a firm believer in free. Mac folks have GarageBand and I'm happy for them but I run my editing on Audacity, a free tool that runs on Windows, Mac, and Linux platforms. There's been some work done in the community on it, but some of the newer releases are flawed (IMHO) and failed to encode MP3's cleanly. I'm running 1.3.2-Beta and it works perfectly for my requirements.

It has some drawbacks. It can (and does) crash if you don't have enough memory installed. Audio editing takes a LOT of horsepower to do easily regardless of your software. You can avoid a lot of the problems by working on ONE project at a time. Close Audacity. Then open it again to work on the next.

Also note that Audacity has project files which can take up a LOT of room. Make sure you archive those off to an external drive regularly or you'll fill up a harddrive pretty quickly. These are important files - ones that you'll need if you discover a problem with an episode down the road and need to remix.

One last note, pick the "more compatible" option when saving the ID3 tags. While the "more flexible" is attractive, several of the MP3 players don't display them properly and it causes problems for listeners who are trying to listen to your podcast.

We have been using Audacity as well and it really works great. In particular, if you're mainly just recording your speech, it is more than adequate.

No matter what audio editor you use, you should save often during projects, and then go back and delete the interim versions that you won't need again. The space project files use can add up quickly.