The fastest and easiest program I have used is windows movie maker. Just google it or limewire it.
Then basically with the program installed and running you will have to import your video files. Once all video is added into windows movie maker you have to drag the clips to the timeline at the bottom of windows movie maker. Once all your video is placed in the timeline import audio, and drag into timeline. The audio timeline is below the video timeline, I think 2 down. You can make the audio file play just as long as the video by going to the end of the audio and dragging it back and placing it where the video ends. Also you can right click on the audio and set it to fade in and out. I use the 3second fade in technique. After that save the file to your computer, windows movie maker will ask you how to save it. Just play around, try to make the video as clear as possible while viewing full screen, but without making it 400MB.
Hope that helps out some.
