I do things a little different than
@WiglWerm. We use mulch in the bottom of the coup, it's a very good mulch called black gold. I put a very thick layer and the hens love scratching around in it for worms. In the indoors part where the nesting boxes are, I use pine straw. The smell of the pine is a deterrent to mites. I also put some in the bottom on top of the mulch. The hens make little next everywhere so the pine straw serves 2 purposes in the bottom. It gives them nesting material and puts a layer down that is easy to rake up at cleaning time. I personally don't use the poop in the garden. I have a fear of solmenilla. I know people do it but not me. I usually put it in one of those brown paper leaf bags along with other yard refuse like leaves and trimmings. We have no problem with smell. People are surprised to find out we have hens.
I do use a dusting bowl. I bought a huge plastic bowl at the dollar store and dug a hole to put the bowl down at ground level. The bowl is 50% very fine dirt and 50% diatomaceous earth which helps with mites. The hens love their dust baths. They actually line up and take turns. If one takes a little too long, they get run out. I also sprinkle some diatomaceous earth on their feed to keep down internal parasites. My hens do get vet visits just to make sure they are healthy. I figure I am eating what they produce so I want my food coming from a healthy source.
As far as extra work, yep they are work. But keep in mind you are caring for a living creature that produces food for you. In the end it is worth it. I also think it is a great experience for kids, the educational value is priceless.
I almost forgot, we do use a heat lamp although not much this winter. I also recommend a heated bowl for water. Mine has a wire thing on top to keep them from sitting on it and pooping in the water.
I think I answered all your questions but if you come up with more....just ask. You'll find a thousand different ways to care for chickens, do your research and you will find the one that works for you after some experimenting. Hens are very curious and like to try new things, have fun with it.