How Can I Edit Audio Tracks For Free?

There are a number of free software packages that you can download over the internet and use to edit your music files. These include REAPER, Audacity, Audioblast and Solition II.
REAPER will allow you to arrange, record, mix, edit and render audio. One can easily fade, split, pitch, shift, loop and copy media.

Audacity is a digital type of sound editor that can be used with Windows, Linux and Mac OS X. Sound input can be from the line input, microphone or other sources. Audacity can be downloaded for free from the official site of Audacity. The website address is audacity.sourceforge.net. The software is capable of performing a number of functions including Recording Live Audio, Converting records and tapes into CDs or digital recordings, change or alter the speed and pitch of the recording etc.

You can try Audacity at audacity.sourceforge.net
I personally use it on a daily basis. It is very easy to use and one can mix, edit, convert, sample, record live performances, split, shift, loop, add effects, fade and a lot more. After you are finished with a track, you can be assured that it is professionally done.

Good luck with your project.