This phrase means to pay someone to do something for you. Typical examples are:
- getting your hair cut
- getting your clothes dry cleaned
- getting your oil changed
- getting your nails done
Use one of these phrases whenever you're talking about one of these kinds of services:
Hey! Did you get your hair cut? It looks nice!
I always get my shirts cleaned at this great place on 35th Street.
(Talking about taxes) I'm getting them done by a real accountant this year. It's just too complicated to figure out on my own.