By Gene and Katie Hamilton
You'll find contractors who specialize in deck and deck rail building listed in the Yellow Pages under "Deck Builders". Many lumber yards and home centers where decking material is sold offer deck building and designing as part of their "installed sales" service. Or use an online referral service as a resource or type "deck railing in (your city)" in a search engine like Bing, Google or Yahoo.
Of course, a referral from a neighbor or friend is probably the best endorsement you can find for any contractor.
When talking to a deck builder about a new railing ask about the local building code requirements to make sure the new railing will comply with them. There are specific spacing and height criteria to meet so the railing will be a safe and secure structure.