American FactFinder - Recently updated, the new American FactFinder now offers a wide assortment of search, display, and save options within a much more powerful search engine, and access to significantly detailed data sets related to population, housing, economics, industry, and geographic data. Quality video tutorials are available to smooth the transition to the new and enhanced features.
U.S. Census Bureau Quick Facts Quick guide to demographic data at the federal, state, and county levels
U.S. Census - The Census Bureau serves as the leading source of quality data about the nation's people and economy. This is a good source for your demographic data. You are able to limit or narrow your data sets to a specific county or city.
Statistics for Specific Industries - Provides information from federal government agencies on seven major industries - agriculture, banking, energy, environment, health and safety, housing, and transportation. Displays 3-5 of the best data resources for each industry. Many of the resources referenced provide information about supply, demand, and pricing; some furnish forecasts & top industry news.
Market size, market share, and market growth can be hard to find, but here are some standard sources to try. Please contact a librarian if you run into problems trying to locate this information.