Most "certified coaches" are dealing with kid's JOAD programs.
I read
Bernie Pellerite's Book Idiot Proof Archery and got a lot out of it.
Shooting archery is more like shooing freethrows than running up and down the court playing the game.
It's about learning a stance and repeating a shot sequence over and over. Once you know what a good shot feels like it is just training your body to do it over and over.
Where a coach comes in is the mental part of it. Giving you the confidence to clear your mind and overcome target panic, for example.
if you are going to pay a coach, have a goal in mind . What do you want help with? Shooting form? Bow setup, reading wind at long distance? You have to have a clear and measurable goal.
For most hunters, a good shop does a good job and does it for free. At every club shoot there is always a guy who knows it all and will coach you for free without you even asking. (we usually try to avoid those guys)
If you want to shoot FITA or go to the Olympics, USA Archery would be the best place to look.
If you want to be a better hunting archer, time spent on the range with other good shooters is your best bet.
If you want some feedback on your form and bow setup ask the shop for help.