Nice coop! They call that kind of coop a "chicken tractor" because you can move it around to give the chickens fresh grass as they eat it down.
We have had chickens for the last fifteen or so years. Right now we only have five (4 hens plus a rooster), but we have had as many as 30 in the past. We used to let them free-range in the day and lock them up at night, but we had lots of problems with predators. One fall we lost 21 chickens in a month to a Bobcat before we trapped it. I got really tired of fighting wild animals (bobcats, raccoons, skunks, coyotes, and hawks) so now we just keep them in the coop which has a 6x12 enclosed yard.
Here are some random chicken photos I dug up, all pretty old, except the one of my daughter in front of the coop:
[great pics Dan.. love the chickens.. and the cat thats laying next to him.. and baby pic.. so adorable