The federal government releases data through a number of agencies. The majority of this data is available for counties and not communities. Some of this information is more easily accessed through other websites specifically for Oregon (see post here).
American Fact Finder
http://factfinder2.census.gov/faces/nav/jsf/pages/index.xhtml
** Most of the data from the 1990 2000 Census and the American Community Survey are available on Oregon Explorer
This website stores data collected by the US Census Bureau. Available data sources include: American Community Survey, 2000 and 2010 Decennial Census, Annual Economic Surveys, Surveys of Governments, Economic Census, and Population Estimates. For an overview:
http://factfinder2.census.gov/faces/nav/jsf/pages/what_we_provide.xhtml
Bureau of Economic Analysis – Regional Economic Information Systems
** Most of this data is accessible through the Oregon Regional Economic Analysis Project
Data available for counties and metropolitan statistical areas. Key variables include employment by industry and components of total personal income, available from 1969 – current.