By David A. Fryxell
Where to find US census records.
Census data from various counties and states are available in published collections such as
Tennessee 1850 Census Index (Heritage Quest) or
Greene County, Pennsylvania, 1820 Census by Mary E. Shultz (Heritage Books) and on a variety of free volunteer-transcription sites, such as
USGenWeb.
The
FamilySearch Record Search Pilot Site has expanded its census coverage to include indexes for 1880 and 1920, and indexes and record images for 1850, 1860, 1870 and 1900. Subscription site
Ancestry.com
offers images and indexes for every census from 1790 through 1930; subscription site
Footnote plans to add the entire run of the census to its 1860 and 1930 records and indexes. Your library may even subscribe to
HeritageQuest Online, which has images for 1790 through 1930 and head-of-household indexes for some.
Visit your library to see if it subscribes to Ancestry Library Edition, a version of
Ancestry.com 
that includes all the census records. Your library or Family History Center may offer patrons the use of Footnote.
From the May 2010 Family Tree Magazine