Audacity - Audio editing that is: free, easy, powerful and did I mention free?
Need an application to record or edit sound? Try Audacity. I personally think it is one of the best open source tools I have ever used. It runs on Windows, Mac and Linux and doesn’t require too great of resources. It will do so many amazing things including import and export MP3’s, WAV’s. 
It allows you to do multi track editing so when you are doing things such as building sound effects, you can easily adjust one part of the effect instead of having to mix everything down to a single stereo track! It comes with a ton of built in effects that you only get with the expensive sound programs all for the price of Free!
The Audacity team is constantly making improvements to the 
software to make it even better all the time. I use it with my Peavey USB mixer to record whatever I need and it works great. Audacity also works great with the Snowball from Blue (A USB microphone) and many other USB devices.
Whenever I worked on sound at UW-L be it for the sound design class or for a show, Audacity was my best friend. It made my life a whole lot easier than using the other programs that people have to pay for!
This software is great for people trying to create podcasts with Windows. It is very simple to record and edit your audio. What I usually do when I want to create a podcast is start in Audacity with recording and making editing changes, then I will export the file to MP3 and move it over to Garageband (Mac application) for final touches and to make an enhanced version with pictures.
Check it out at: http://audacity.sourceforge.net
For more documentation go to: www.audacityteam.org/wiki