Word of mouth. Ask around your friends & coworkers. Get someone who is known to other people you know, that’s also the safest.
For any job you need to get done, the best way is to have multiple options.
I think the best way is to ask your neighbors or friends if they recommend anyone. This way you know the contractor did a good enough job because your friend is willing to recommend them to you. Plus, a contractor always loves getting referenced by customers. They always seem to do a better job so they stay in good standing.
If that method doesn’t work…
I would meet a few contractors for the same job. Go to the yellow pages and call up some contractors (I’d say about 3) and ask them to come over and give you an estimate on the job needed. This way you can meet the person who is going to perform the work, and you can compare prices. Don’t go for the lowest price all the time. Go with the reasonable price, or even better, go with the contractor you feel will do the best job. Even if it will cost you a little more.
At least you will have peace of mind.
Contact local Better Business Bureau, try City Hall, or go to a reputable Home Supply Center and ask for referrals.
Check with your local chamber of commerce
better business bureau