How do i make films like Twilight using actual film clips?

On WMM i can only make films using pictures but i would like to make music videos using film clips. How do i do this please?|||The only thing I can think of is using Windows Movie Maker. Convert the video clips into .avi file, import them to Windows Movie Maker, add whatever music you want and change the audio output to music files rather than the audio from the video file.