Information on owning chickens, help ?

I'm actually surprised at the lack of info on the web concerning owning and caring for chickens .. I'm planning to get a couple of lil Bantams for egg laying and I was just wondering how costly they are to maintain as I don't really have too much money. Also how large would their coop have to be, what's the best possible way to protect them from cats and other animals (As I have a fair few lurking about where I live) Although they've never entered my yard. And how much room do they need in general ? It'd be great if you could help, thanks.