Audio Editing Recommendations
When it comes to audio editing there is really only one program to recommend: Audacity. There are a number of audio editing applications that are packaged with commercial programs like Nero or Roxio's Creator line but they all seem to be lacking by comparison.
"Audacity® is free, open source software for recording and editing sounds. It is available for Mac OS X, Microsoft Windows, GNU/Linux, and other operating systems." (from their website)
Audacity is the only audio editing program I use! I used to be a fan of a product from Syntrillium Software called Cool Edit 2000. Unfortunately for its user community, Syntrillium sold the Cool Edit program line (primarily for Cool Edit Pro) to Adobe some time ago. Adobe has adapted the Cool Edit Pro features for use in their products and effectively killed Cool Edit 2000.
Audio editing is a combination of art and science. Audacity, with the package of LADSPA plug-ins, does just about everything that I want in an audio editor. I currently use the 1.3.x line of "Beta" code, which is more stable than many production products. I like the features and interface of the 1.3.x versions much more than the 1.2.x versions.