What would you look for in a non-profit organization as a potential employer?

How do you know if it is a reputable organization? Where can I go to find that information?

With a for-profit business, I can check places like glassdoor.com or find public reviews on Yelp.

I have found a job listing that sounds interesting and more fulfilling than my current job. I want to avoid stepping into a bad situation if possible. I know that can happen in any job, but I feel that I should do some research first.