Youtube videos...I hope that someone can help me. please read...?

You know all those fan made videos of shows? Like with Laverne & Shirley or 7th Heaven or Degri or whatnot? The ones where you use a whole bunch of scenes together and you have some song playing with it? I need to figure out how to do that. Does anyone know how to make them? It would be much appreciated if you could help me out. Thanks.