Then I used Windows Movie Maker to record a narration track. It saved the narration as a WMA file. Later, I decided I'd like to add a music track (after some tough negotiations with my daughter to let me use one of her original guitar pieces). Since Movie Maker only allows one audio track, I needed to mix the music and narration externally.
So, I downloaded and installed Audacity. Adding a WAV file of my daughter's music was easy, but the WMA narration file could not be natively imported into Audacity. So, I found a program called SUPER which would pretty much convert any audio and video formats into any others. It's main selling points are that it's free and it already includes the codecs you need.
With the audio mixed, it was easily imported back into the movie. Some titles and credits were edited in adn that was it. I exported it to a WMV file and then uploaded it to YouTube.