we had one, she was AWESOME!!! but we moved away
we paid her as cash in hand.. she had another job where she was getting paid on the books.
we paid between $12-15 ph depending on the time she had the kids. ie if she only had to do dinner bath then bed and they were asleep for most of her time she got the lower rate, if it was daytime she got the higher rate.
that was for 2 children.

there are agencies you can go through and some will be able to claim CCB for you, but they are often time limited(may be fine for your job) agencies can be exxy..

we ran an add through the local paper