..their are many different "list" that will suggest contractors to do your work! Problem is you pay to be a member or we pay for each estimate we go on... bottom line is someone pays for this service!
Most do NOT ask us for any documentation of insurance just our "best" pictures of work we have done which can be taken from anywhere...
Best way ... do your own research, ask a friend that had work done, ask contractor for references, visit projects that he has done, check with BBB of any complaints...