Hi Lee
If you want a free option then go for Audacity. It's pretty good for a free editor. We use Adobe Audition here to edit our podcast - but it will cost you.
There is also another paid for option that I keep meaning to try called Hindenberg. It has a great reputation. I think it costs around $80.
There's another free option and that's a Chrome web app called Aviary audio editor.
https://chrome.google.com/webstore/detail/ajiijeebjcmkhdplmollbjpljcnelfhnYou might be interested to read this post on tips for audio. It's from 6 months ago but still relevant
http://blogs.journalism.co.uk/2011/06/07/ten-fantastic-apps-tips-and-tools-for-recording-audio/Sarah