What Census data (and other government data) gives you:
Much of the demographic data you will need for your community health assessment is available from the Census Bureau, including from American Factfinder and the American Community Survey.
But not everything. Some categories are not available from the Census directly. These include:
What you can get from Census data includes:
The Decennial Census is a constitutionally-mandated count of everyone residing in the United States. It doesn't matter if you are a citizen or a non-citizen. You still get counted.
The U.S. Constitution requires this national census once every 10 years (beginning in 1790) in the years that end in 0. The central statutory purpose of the census is to determine the number of seats each state will have in the House of Representatives for the next 10 years.
In addition, the Decennial Census:
American Community Survey — Detailed portrait of the U.S. economy (businesses and industries) once every five years in years ending in 2 and 7. Data is published for more than 1,000 industries, 15,000 products, every state, 3,200 counties, 10,000 cities and towns, and the Island Areas.
Annual Economic Surveys — These surveys are annual, quarterly, and monthly, and they measure everything from capital expenditures for food manufacturing companies to annual auto dealership sales. The major AES surveys are Annual Survey of Manufactures, County Business Patterns/Zip Code Business Patterns, and Nonemployer Statistics Data Sets.
Population Estimates Program — Annual estimates of births, deaths, and domestic and international migration (for example: what is the fastest-growing state, metropolitan area, and county in the United States? What places in the US have lost the most population in the past year?)
A comprehensive list of all Census products is here.