If they do good work they'll be more than happy to brag about it and/or literally prove to you they do a good job. And don't just let them give you a few names, ask them for their last 10 jobs, in order, with names AND dates so you can see all their work, not just work they did for a buddy who will give them a glowing endorsement. That also goes for asking them for a copy of their GC license and bonding/bonded.

Second piece of advice I got from a ward member who got ripped off: never, EVER pay them any money up front so they can buy materials, etc. Nope. If they're running a good business they're making money and should not have to come demanding you pay them to get started. That's total BS and I would immediately walk away from anyone who demanded so much as a nickel down. They can be paid piecemeal as they go.

Third piece of advice: Details, details, details.....in the contract and what is expected by you. Don't want them using your bathroom in the house? Tell them up front. Ask them, too, if the price will drop if YOU end up doing some of the work. Had a guy in my ward I hired for some work tell me that if I want him to do more work then he'd have to adjust the contract so he can be paid for the extra work. Totally fair. Then my son and I did a bunch of required demolition one night to help move the work along. When I asked him about adjusting the contract downward for that he said, and I quote, "The bid is the bid." THAT pissed me off and it cost him a whopping lot more work I wanted him to do in my home. Financially speaking, he cut his own throat.

Good luck!, and take pictures along the way for your wife's family scrapbook. 🙂

EDIT: One other thing....ask them if they're going to charge you extra just for transporting materials to your home. Explanation: That guy above that I briefly hired charged me THREE times what a lumber store would've charged me for some cedar lumber I needed. I went to the lumber store and was buying something else and (I can't remember how) the clerk showed me what the store charged this guy (Jim) for the lumber I needed for the renovation Jim was doing for me. When I looked at Jim's invoice to me, Jim had marked up that piece of lumber 3x what he was charged. When I confronted Jim about it he said "Well, I gotta make money." My thought was, "Dude, I'm paying you for your building skills, NOT to be a delivery man." I could have got the wood just as easily as he could have AND for less because I am offered a military discount. I vowed never again will I be charged for what amounts to a "delivery fee" for materials.