State and local government websites are a rich source of information for your city. Try a few web searches for your city. On one of them include the term "site:.gov" in your keywords. This will limit your results to government websites.
NAICS codes are important to know when you are researching industries. The North American Industry Classification System (NAICS) are numbers that the U.S. Government assigns to each industry for the purposes of collecting, analyzing, and publishing statistical data related to the U.S. business economy.
Local newspapers may have relevant articles. Look for the name of your city's newspaper, and then search for archived stories. If the newspaper is defunct, or you're having a hard time finding old articles, try searching in the Wayback Machine.