We mostly handwaved the mechanics, except to say that wingfolk tend to be thin, muscular, and have incredibly high metabolisms. Winged children are cautioned not to even try flying until they've finished their growth, because their muscles aren't strong enough for it. There are flight schools around the world where winged teenagers spend as long as two years learning to fly.
We concentrated on what social dynamics were involved. We decided that we didn't want wingfolk to be directly analogous to gays and lesbians, so we said that in most places, wingfolk are honored, and considered special in a good way. Almost all of them in the developed world tend to go into creative professions--there are a lot of winged actors, but not so many winged lawyers. There are all sorts of specialists who provide services, like clothes and furniture designed to acommodate the wings, and places where wingfolk can go to get professionally groomed. Because things like getting dressed and grooming usually require help, a lot of wingfolk live communally. In keeping with the semi-tribal ethos, winged fashion tends to involve a lot of body art, especially tattoos.
...and now I want to go poke at one of the pieces I started last year, about two rival winged skiers (there's actually separate Winged Games in conjunction with the Olympics).