You can find carpenters with experience installing a suspended or drop ceiling at contractor online referral services and at the retailer where you purchase the material. You'll see an "installed price" tag in addition to the cost of the ceiling tiles that covers the installation. Many retailers offer this installation service and manage scheduling the work and guaranteeing your satisfaction. Or type "ceiling installer in (your city)" in the search box of a search engine like Bing, Google or Yahoo. If you buy the ceiling material online, you'll probably find an "installer locator" option to find an installer in your area.