Don't go nuts. We went from 6 to 40 in four years (though we're trying to get back down in the 30's). Some people jump up that fast in a single season. The biggest problem is the minimum order size for most hatcheries is 25, though some do 15. 25 is too many for a first-timer. If you need to, just check Craigslist in the late winter/spring and there will be plenty of people with chicks for sale, especially the more common breeds.
I assume you have or will have part of your coop set up as the "henhouse," where they roost and where the egg boxes are. Will that be your 4 x 8 room? There are guidelines online for how many square feet to allow per bird, and I think it is 4-6 sq ft per bird if they spend at least half their time in a large run/yard or free range. You have to consider that in the winter, especially like last winter, they will be indoors a lot and that 4 sq ft per bird gets a little tight. That's where we are now (with a very large chicken yard and attached garden, which they are currently "deforesting" with great joy). Chickens don't particularly enjoy walking in snow. You won't get as much as I do around Indy (I'm from L'ville, so I joined this thread), but you will get some unless you are in southern KY.
Start small. There is this thing called "chicken math" which is responsible for the mass proliferation of chickens to one's maximum capacity very quickly. Ours aren't "pets," with a few exceptions, but we do like almost all of them. The jerks tend to wind up in the freezer sooner for sure, without tears (yes, there's that to be considered down the line, too--you can't allow chicken math to overtake you if you plan on keeping your birds until they die a natural death, which can be 8-10 years). We will let some live their whole life because they are either super good birds (at teaching other birds), or we just love 'em because they are particularly sweet and gentle. I would get between 6-10 to start, and see how things go. You want to be sure you like it. Almost all of us on here are nuts about our birds, but some people get them then decide it isn't for them, then the birds wind up being given away or sent to chicken rescues--but that isn't a great backup plan.
Oh, I almost forgot one other breed I do not recommend. We got three Jersey Giants. They are TOO docile to keep in a mixed flock, in my opinion. They are huge and lay big eggs early on, but 2 of our 3 were picked on very badly by the rest, and only one was co-boss with an Australorp. One died, we slaughtered one that became an egg eater, and we still have one, but will slaughter her before winter. She lived last winter for 3 months in our garage because the other birds wouldn't let her stay in the henhouse, and she almost froze to death. We love her, but I'm not having chickens in my house. She looks terrible because of all the feathers the others have pulled out of her, but she gets plenty to eat, has good body weight, and lays regularly. They also eat a lot more than standard sized chickens for the same egg production, but it was an experiment we tried, and it failed. Australorps aren't as big, and are egg machines, and easy going. So, we're just as happy with them as our black chickens than the Jersey Giants, which were also black.
Last thing, but very important. You really should bury 1/4" hardware cloth around the complete perimeter of your coop and run, or you will wind up with predation after dark/before sunrise, and it can be devastating. We have only lost one single bird to a predator (probably a mink) in four years, and the hen that was killed stayed out after dark. Our fault for not putting them away at dusk that night. Friends who just use chain link or chicken wire find that small but vicious predators can get in, like mink/weasels. Racoons are also awful, as are hawks. However, domestic dogs kill the greatest number of chickens. Your choice of an Anatolian is good, but you need to do a lot of reading and/or rely on a great trainer to be sure that the birds are safe from the dog, and that people are safe from the dog. Anatolians don't like anyone but their family members. One of our neighbors has a Pointer that jumped over our fence and ran of with a hen. Fortunately, she was not killed. We had a lower fence then, now have a 5' deer fence for the yard/garden, but the entire coop has hardware cloth buried about 10-12" deep. Hubby rented a trencher to do that right after he set the 2x4 uprights for our coop. Most of our coop is actually hardware cloth except for the henhouse, and the roosting area in our two rooster "apartments"/breeding pens. We added 1/2" of polystyrene insulation to the henhouse exterior last winter, covered that with Tyvek house wrap, and just now are finally siding it with galvanized steel roofing material so it doesn't have that "West Virginia" unfinished look any more. I love the fancy painted coops that look like little houses, but we wound up spending about 5K over the past four years on what we do have, so I can't imagine investing much more!
P.S. Buy this book. It's as close to the Bible for backyard flock owners as there is.
http://www.amazon.com/The-Small-Sca...tmm_pap_title_0?ie=UTF8&qid=1411692925&sr=8-3