Looking up their license for complaints is a good idea.

I looked at the state's psychological association to verify that he had a license , and how long he'd been in practice, but that was it. I tried googling specifically for reviews, but didn't find any (*frustrating!*).

He also linked his business FB page to his website, so I read through several years of his past posts to try to get a feeling for who he was, before deciding to call. Not sure it actually helped, but it felt like I was doing something!