Below are links to some popular software programs that can be used for recording and editing audio for your digital stories. Microsoft Photostory 3, moviemaker etc have built-in audo recorder and the ability to add music.
Audacity is a cross-platform digital audio editing program that lets you record, edit and mix narration and music. It is recommended for those just starting out with audio editing and best of all, it's available for free. (Use By both PC and Mac Users)