I know that sounds silly, and makes many thing back to Mr Ed, but with the gestures they give off, how can you tell what is what? I'm sure they cant really talk, but there is always body language right?

There are many ways where you will know what the horse is telling. You will mostly know what they are telling you through the reactions on their faces. Here is a site (http://www.angelfire.com/tx2/kidshorses/bodylang.html) where you could read on how to know what your horses are thinking.