So I have some newbie questions: My current flock consists of 8 chicks that are all roughly the same age-- about 8-10 weeks. Should I be looking for new chicks about that same age for the most seamless introduction (or would slightly older/younger be better)? Will they need as long of a separation period as if I had adult hens to worry about? And what about the coop? I only have one... How will that work? Sorry if these questions are silly, but I want to be sure I'm ready and doing right by the chicks I already have, as well as the ones coming in. Any advice would be greatly appreciated!
Unless you are buying day-olds, most people recommend quarantining new chickens for at least a couple of weeks to a month, to make sure they are free of disease and parasites. You could do that in a garage, basement, shed, whatever is available.
I had the same problem as you with my coop. At first, I just sectioned off a small area under the poop boards with chicken wire, and let the chicks get acquainted with the rest of the flock for a month or so that way. It was a real pain crawling around to fill food and water. Since then, I have sectioned off a larger area with an actual door (small door, but it works), and I even divided my run, since I have 2 pop doors.
When there are no chickens to introduce, I can leave the door open, to make it more spacious.
I usually let new chickens get to know the flock through chicken wire for a month. The main thing is, don't mix them until they are similar size. The chicks can't defend themselves against adult hens.
Now, I am adding another large coop!