Likely your roof already done . Advise I offer not limited to roofing .
I frequented building supply places as contractor for better pricing ( I only worked on my own property ) for years prior building my home . Became good friends with workers there . When forced to pay for job I could not handle my selection criteria.
Hey buddy what are the 3 best contractors you would use on your own home ( insert your task here ) ? Ask at all preemmen commercial building supply stores . After 3 or more stores where is the overlap . That is your contractor pool .
Qualify next question by telling with how long you plan to live in home . What materials would you use ? Any warranty issues you have observed ? Do your web research on once again overlap suggestions .
Last suggestion likely cause some folks shit bricks . I always had super relationship with building inspectors ( I do not cut corners ) . Name all the overlap contractors one at a time . Look into inspectors face as you state each name . They cannot recommend single contractor but you may receive good feedback from facial expression .
Worked really well for me .
Good luck Shane