Audacity

Audacity is a free, easy-to-use audio editor and recorder for Windows, Mac OS X, GNU/Linux, and other operating systems. You can use Audacity to:

  • Record live audio.
  • Convert tapes and records into digital recordings or CDs.
  • Edit Ogg Vorbis, MP3*, and WAV sound files.
  • Cut, copy, splice, and mix sounds together.
  • Change the speed or pitch of a recording.
  • And more!

It can be downloaded from http://audacity.sourceforge.net/download/

Documentation: Using Audacity - Word (1MB)

* To export to MP3 format, you must also download the free LAME encoder.