What a great idea...build the coop BEFORE getting the birds!
I would, like most everyone else, have made my coop larger. It is a converted club/tree house that we chopped off it's stilts and moved to another side of the property. At 8x8, I would have thought it would hold as many birds as I wanted, but my problem is, I always want more
I used an old upper kitchen cabinet inside the coop to hold DE, poop scraper (aka paint scraper), metal dust pan (also poop scraper), and misc odds and ends. It would be great if there were room inside the coop for storing feed, but I need all the floor space I can get for by chickens.
I wish I would have thought the run out more. It is large, about 25x35...and will therefore be hard to cover. I did not think about covering the run before. But last winter I lost 2 birds in 3 days due to predators (fox and hawk) Two strands of electric fence spaced 12" apart running around the run will help deter foxes, but not hawks. I currently have deer netting stretched across the top, but with the snow we had last night, I can see this won't last for winter.
I live in NE Ohio, and we have not insulated our coop. While we do have ventilation that is not closed off in winter (although windows are closed to only 1-2" openings), the chickens did fine all winter. Do invest in a heated waterer of some sort - ours is the 3 gal heated plastic water...works great.
When we had the most birds (15) in the coop, our 4 nesting boxes were all used...but some more than others. While one nest box would have one egg in it, another would have 7! Think 1 box for every 4 birds. I collect my eggs from inside - no outside door on nest boxes. This makes me do a visual inspection of the coop every day, instead of a quick gather and run back into the warm house, lol! Good luck!