"When possible, choose a contractor through personal recommendations. Try to get referrals from friends or neighbors who have had similar work done.
Call and pre-qualify contractors. Be sure each person is licensed and insured for worker's compensation, property damage, and personal liability. Don't be shy. Most people who've recently remodeled are proud to show off their homes and, if they like the contractor, they'll go out of their way to help him or her secure another job.
Don't automatically choose the lowest bid. If one bid is seriously lower than the others, be suspicious of inexperience or desperation (the latter isn't necessarily a problem). Generally speaking, if a bid looks too good to be true, it probably is."