Where are rodeos held?

I'm doing a project in social studies about different cultural sports and I happened to get "rodeo". A sport from our own culture. I need as much info as possible. I'm guessing it's held in some sort of arena...I'm not sure what it would be called? What equipent is needed, Limits to a particular group? How did rodeo begin? and what are the basic rules of the sport? If anyone knows even a little bit that would be great! (and btw this is due tomorrow so i'm kinda in a hurry! :])