I'm glad that you asked this question, I've been wondering about this too.
I babysat for 7 or 8 years, but that was over a decade ago. I'm hoping to use my sister as a reference, since I've babysat her kids, but only a few times.
As a parent, I would use a daycare just starting out. I think as long as you have references from anyone, not necessarily child care then it's still good.