Nonprofit Services -

Population

National

Census Information
Census Bureau: Demographics: http://www.census.gov
America's FactFinder: http://factfinder2.census.gov/faces/nav/jsf/pages/index.xhtml
State & County QuickFacts: http://quickfacts.census.gov/

American Community Survey
http://www.census.gov/acs/www/

FedStats: The gateway to statistics from over 100 U.S. Federal agencies
http://www.fedstats.gov/

Joint Center for Political & Economic Studies: Demographics of Minority populations
http://www.jointcenter.org (Main Page)

Population Estimates
(US Census estimate data: Create data tables by state and demographic characteristics)
http://www.census.gov/popest/

State

Missouri Census Information
Raw Data: http://mcdc2.missouri.edu/webrepts/sdcprofiles3/mo/
MO Census Menu: http://mcdc2.missouri.edu/websas/dp3_2kmenus/mo/
Map: http://mcdc2.missouri.edu/pub/webrepts/mocntymap.html
Circular Area Profiles: http://mcdc2.missouri.edu/websas/caps.html
Tract Number (MO): http://mcdc2.missouri.edu/websas/dp3_2kmenus/mo/Tracts/
MO Demographic Profiles: http://mcdc2.missouri.edu/webrepts/sf3pros/moindex.html

Illinois Census Information
Tract Number (IL): http://mcdc2.missouri.edu/websas/dp3_2kmenus/il/Tracts/
Place (IL): http://mcdc2.missouri.edu/websas/dp3_2kmenus/il/Places/
IL Demographic Profiles : http://mcdc2.missouri.edu/webrepts/sf3pros/ilindex.html

STATS Indiana
Includes updated and detailed statistics broken down to County level.
http://www.stats.indiana.edu/ (Main)
http://www.stats.indiana.edu/uspr/a/us_profile_frame.html?S29?C000 (County Profiles)

Local

Census information by Census Tract:

What is a Census Tract?
Census Tracts are: “Small geographical area established by local committees and approved by the Census Bureau, which contains a population segment with relatively uniform economic and social characteristics and clearly identifiable boundaries averaging approximately 1,200 households.
http://www.census.gov/geo/maps-data/maps/2010tract.html

How do I find a Tract number?
There are three ways:
Look at the tract map provided by the U.S. Census bureau. Under the map menu, choose the county you are researching, then in the menu select “[name of county] Tract level base map.” A .pdf file will open and the Tract numbers are marked on the map.
http://mcdc2.missouri.edu/pub/webrepts/mocntymap.html

Also, the Federal Financial Institutions Examination Council (FFIEC) has a Geocoding system that gives Tract numbers for any given address. 
http://www.ffiec.gov/Geocode/default.aspx

America's Factfinder now includes census tracts and block groups in its information. Search by address or use the "Reference maps" to find the corresponding census tract number.
http://factfinder2.census.gov/faces/nav/jsf/pages/index.xhtml

Business Decision Pro: (In Library Use Only)
Business Decision Pro combines mapping capabilities with detailed demographic and psychographic data to allow businesses to engage in detailed marketing analysis. Using ring-studies, driving times, or preset geographic areas, Business Decision Pro can provide analysis that will aid in site-selection, marketing efforts, or spotting trends that will have an impact on local businesses.
www.businessdecision.info/Login.aspx