Hi,
I have 5 (yes, five) different coops because of having birds of all different ages, which means they need different kinds of food. And I couldn't put the youngest ones with my big ones, anyway, as I think it might turn out to be a massacre. Believe me, I know it's crazy, but it's what I have to do at this point!
If the coop is large enough, I keep the feed and water inside. In the warmer weather, I had the water outdoors, but keeping it indoors now helps keep it from freezing.
However, I have one that isn't large enough and that food and water must go outdoors. But it is covered (and so is the feeder itself) and the food doesn't get wet. I keep a heater under the water so it doesn't freeze, one of those light bulb things and it works great!
My personal preference is to keep the food and water outdoors but not all of the coops have an outdoor area that would keep the food dry. As someone else mentioned, it is hard to see what they are wasting when the food falls into the hay in an indoor area.
Right now, I have some on chick starter, some on chick grower, and some on laying pellets and scratch. I can't wait for the little ones to grow up so I can keep more of them together (as long as they don't attempt to kill each other)! It will be a lot easier to feed them all one type of food.
I also have two young turkeys (10 weeks old) that I haven't let out yet because of their age (too cold, I think, but I'm no expert). I have them on turkey grower (took me a while to find it around here) and, of course, their food and water is indoors.
Just my two cents worth!
Genie