Our coop, which still needs trim, is 8x10 overall, with the actual coop area measuring 6x8. There is a 4x8 room we pass through to one side to enter the coop proper; this is where we keep supplies, food, etc. The run is an entire 8x10.
The poopboard is an idea I found on another site and works great. Since this area gets the dirtiest, I can clean it once a week and save cleaning the entire coop (replacing bedding) for just once a month or more. The roost is positioned above this, and the food and water hang below.
Well above the roost, and mimicked on the oppostite wall, are 36"x12" vent windows covered with mesh to detract predators (we get a lot of skunk, fox, and racoon here). These will have operable windows by wintertime so that we can close them if the temperature drops below freezing; a good bet in Iowa. The coop is also insulated, and with a ridge vent in the roof, the coop stayed vented and tolerable in the 100 degree heat we had just last week. Every time I checked on them, the chickens were hangin' out inside!
We went ahead and built 6 nests for our 6 hens, although most experts say you only need one for every 2 chickens. Our hens happen to use about 4 of the nests regularly, though all 6 have been used at one time or another.
The first time we cleaned the entire coop I needed to rotate the compost pile, but the old stuff wasn't quite "cooked" yet. We threw it into the run on a whim, and it has worked beautifully! Not only do the chickens love scratching in it, but they are helping to finish the process! We plan on continuing this practice.
All in all, we have 6 very happy hens!