J.S.
I live in IL and provide licensed daycare in my home. I have a membership with care.com and I also put advertisements on craigslist.org. I've come across many families with both of those. If you have a local organization, such as DCFS (dept. of child and family services), they can usually provide you with some referalls. What's nice with DCFS is they will ONLY refer you to licensed providers, and all licensed providers had to have passed a background check thru your state. They NEVER charge you for their services. There is also sittercity.com which I've heard really good things about as well.
Good luck!!