Yup, audacity is a good choice, as noted by the previous two posts. Another option for low-cost audio editing is WavePad (http://www.nch.com.au/wavepad/index.html
). Also, a free-but-you-get-what-you-pay-for video editing option for Windows users is Windows Movie Maker, included as part of recent Windows releases. With it you can merge captured video and audio, add (very limited) titling, and do some basic editing. Its advantages are simplicity and availability, though obviously there are many more robust tools.