Does anyone here know of a good resource online to find good doctors in specialty areas?

I know there are a couple in Des Moines, IA that are supposed to be good at melanoma surgery, but they don't subscribe to insurance...cash only.

Apparently I don't have my wits about me to find a good online resource.

My mom was just diagnosed with a melanoma on her face, and I don't trust the oncologist where I live even one little bit. I'm in central Iowa.

Anyway, thought somebody might know and TIA.