Save the Cat

They say this is the last site you need to visit for screenwriting http://www.blakesnyder.com/media/

Save the Cat helps to develop motivation and flesh out characters in narrative writing. It's called Save the Cat because when you want the audience to identify with your main character you need to provide something  cute and cuddly that he saves so the audience connects. On the contrary, your villain is more fully fleshed out when he kills the cat.