Audacity

Audacity is a free, easy-to-use, multi-track audio editor and recorder for Windows, Mac OS X, GNU/Linux and other operating systems.  Audacity can be used to record live audio, record computer playback on any Windows Vista or later machine, convert tapes and records into digital recordings or CDs, edit (WAV, AIFF, FLAC, MP2, MP3, or Ogg Vorbis) sound files, edit sounds, use numerous effects like changing speed or pitch, and many other features. 

Support Links

Audacity 2.0 Tutorials
http://audacity.sourceforge.net/manual-1.2/tutorials.html

Where to Access/Download

Audacity 2.0 can be downloaded for free on any computer by going to the following link and selecting the correct Operating System:
https://sourceforge.net/projects/audacity/