how do i make my own commentary and then put it on a vcd

I hope this is the right section to ask this question. Anyways, how would i go about making my own commentary to a mpeg-1. I just want to make it with my computer microphone, and be able to record it while watching the video full screen on my computer. Then, how do i make sure the timing is right? Do i just hit record and play at the same time? And then is there some kind of program i could use to mix the audio files together at the levels i wanted? Any help would be appreciated-thanks.

 

Well I think if you use something like "Sound Forge" it will Let you Import your File and record audio then let you Mix it with the Files audio Track then re-render the audio that you would then have to Mux with the Video....Cheers