Where could I find a list of certified babysitters in my area?

I am looking to find a certified babysitter with very good references and who is dependable and reliable with children, and also who is affordable. Where would I look in my area (Southwest Florida) to find a certified babysitter? I am extremely nervous about leaving my kids with anybody else but me, but my husband and I really do need some time out every now and then. I will do my own research on the candidate as well as get to know the person a bit before I would leave them. Any answers would be appreciated!