Is there a central register of proofreaders and editors?
Where can I find a proofreader or editor?
You need to do your homework and take a bit of time to do some detective work – sort out the apples and pears.
(Yes, I know that's a rubbish metaphor, and it should maybe be apples and oranges, or separate the sheep from the goats, but I love this picture!)
It has never been easier to vet someone now that we have the internet.