Anybody have experience working with a career/life coach?

I think I'm finally ready to make a career change, but want to do it intelligently. I'm fairly certain that I want to spend the rest of my working life in the nonprofit sector, and am beginning to research my possibilities. I don't want to go it alone...does anyone have any advice, etc., as to what to look for in a career coach? Any pluses, minuses, red flags, etc., that I need to be aware of going forward?

Thanks....!