I recently needed to create a voice mp3 file for my site www.TheAwakening.com. After very little searching, I found this cool free audio editor that makes it a breeze to record and edit audio files from a microphone. Not only is it great editor and free, but it is also open source.
If you are making a podcast, playing with some audio files or want to build your our audio files with multiple tracks, try out this cool product at:
http://audacity.sourceforge.net/
Note: For MP3 capabilities, you will additionally need to download the “Lame Encoder”, but there are easy instructions on where to get that file along with how to use at at the Audacity site.