If you have had any experience with hiring a contractor before, the same guidelines should be followed for a metal roof installation. From asking friends and family for references of contractor's they'd recommend to checking their references and background against the Better Business Bureau, these are major steps that should be performed with any job.
But due to the nature and uniqueness of metal roof installation, there are a few key differences that must be taken into account as well. Since it's very much a specialty trade, different skill sets are needed than most typical roofing jobs.
Due to its unique nature, you may need to find unique ways to come up with qualified contractors. One of the best places to find a contractor that specializes in metal roof installation is to ask the manufacturer directly for a list of companies in your area. Obviously, this will require that you have chosen a metal roof type and manufacturer before you set out on your adventure to find a contractor to install it but this may be just a reason to do so.
Also, you can ask architects in your general area that design commercial and residential buildings that utilize metal roofs for input. Finally, there's always the internet and your local phone directory.
When turning to the internet, try to find a contractor-referral website first that requires their contractors to go through some sort of pre-screening process. By utilizing this type of service, you will save yourself the hassle of eliminating false leads and will be put in contact with contractors in your area that have already displayed the necessary attributes to do a metal roof installation. This can save you time since and undue stress along your journey.
Once you have built up a list of possible contractors that may have the necessary skill set, it's time to find the best fit for your project. You want to look for roofers with at least three years experience in metal roof installation. Check to be sure that your contractor carries insurance, is bonded if your job is large enough to warrant it, and that it's valid. Also, be sure to obtain a contract from your contractor once you've decided on which one suits you best.
Be sure everything is excluded including cleanup of the job site, a tentative completion date, cost, materials used, and any other details that were in your written estimate. This will serve as a security blanket for both your contractor and yourself.