A friend of mine just built a coop out of one of her stalls in the barn. She just cut a hole in the bottom of the stall door so the chickens could come and go into the barn aisle out into the horse lots.
Hers are pretty free from above. Mine are totally inclosed. I'll take some photos and post them here in a bit.
I built a roost for them at night, just out of old left over wood and some dowel rods. I put in a tree branch but they prefer the dowel.
I got my laying boxes at an auction sale, but I've seen people use all sort of things like barrels or boxes stacked up. You need 1 box for every 2 laying hens.If you have 12 pullets you will need 6 boxes. I've gotten fake plastic eggs from different sources over the years but my friend just used plastic easter eggs in different colors. They seem to be working fine.
Sources:
McMurray hatchery is a great source for stuff including chicks
Eggcartons.com is another of my favorite online sources for egg cartons and just chicky stuff At one time they were the cheapest source for egg cartons
Most farmers markets will not allow you to sell eggs in reused cartons, just an FYI