Word of advice.
Animals express themselves in unique and very different ways from us. Taking the time to learn the body-language of animals you know you will be around shows respect for them, because it means you are listening to what they're telling you instead of just assuming you're in charge and you'll be fine. If people took the time to learn about animal's expression, there would be less attacks from wild animals. In one documentary, divers even observed the language of great white sharks amongst each-other ; through recognizing the signs of aggression and displaying submissivness in a way the sharks could understand, the divers were able to swim close to the sharks for hours. Amazing, huh?
That said, here are some guides to cat body-language:
http://messybeast.com/images/cat-chat3.png
and
http://messybeast.com/images/cat-chat1.png
