I agree with many of the things already said. No one will clean the same way you do. If you can accept that, you're half way there. Get references from folks you know. Meet with the cleaner and spell out what you need/want done; type of cleaning products you prefer (or that manufacturer recommends for given flooring/appliances); what you are okay with them not doing. Another thing to remember, pick up 'droppings' yourself and put them away. My attitude always was 'I'm paying them to clean, not tidy up'. DH leaves stuff everywhere. He was always good about picking up for the cleaning folks - not so much for me, but that's a different issue. I'd rather put my things away where I'll know where to find them again instead of someone else putting them in a place I'll never think to look.
I had several different cleaning people over the years while I was working. Never had a theft issue but did have some breakage. As others have pointed out, this can happen to you as well. If you want to be there, out of the way, a couple of times until you feel more comfortable there's nothing wrong with that.
I wish I could justify having a cleaning person now! Kinda hard to justify when I'm not working though.