Census - Non-Name Rolls

Atlas of County Boundary Changes in Virginia, 1634-1895 - Reference Room, 4th floor: G1291.F7 D6 1987
Shows the evolution of counties in Virginia from colonial times to the end of the 19th century.

Descriptions of Census Enumeration Districts, 1830-1950 - Microfilm cabinets, Government Information Reading Room. 
Available:  Virginia only [Gov Info Microfilm #7168].
These are descriptions of the physical area in which each census enumerator took the census. Literally, they describe the neighborhoods and roads the enumerator walked up and down to interview households.

Guide to Genealogical Research in the National Archives - Shelved on Row 13, Gov Info Reading Room
Describes a wide range of Federal records available for genealogical research in the National Archives.  Chapter one, "Census Records" is particularly useful for its detailed descriptions and examples.  For a full description of the title see Publications web page linked from the the National Archives' Genealogy Page.

HeritageQuest
Full text and indexing for census name rolls, 25,000 local history and genealogical books, 1.6 million genealogical and local history articles, and Revolutionary War pensions and warrants.

Map Guide to the U.S. Federal Censuses, 1790-1920 - Shelved on Row 13, Gov Info Reading Room 
Shows county outline maps at ten-year intervals, the old county boundaries being superimposed over the modern lines.

Non Population Census Schedules, 1850-1880 - Microfilm cabinets, Government Information Reading Room.  Available:  Virginia only
Guide - Micfilm 1883 available electronically and with other microfilm guides.
The non population schedules after 1880 were destroyed by Act of Congress and no longer exist. The non population census reports include the following schedules: 
Mortality Schedules - lists name, age, sex, color, place of birth, occupation, month of death, cause of death for people who died in the year ending June 1 of 1850, 1860, 1870, and 1880.
Agricultural schedules - lists farms in each county, giving the name of the owner, agent, or manager.
Industrial Productions schedules - lists businesses or individuals producing goods valued over $500/year
Social Statistics schedules - lists various "social" information such as valuation of estates and annual taxes; lists of colleges, academies, schools, libraries, newspapers, and churches; crime statistics; and wages.

Federal Mortality Schedules, 1850-1880 -- Government Information Microfilm Cabinets
Gives information including name, age, sex, color, place of birth occupation, month of death, cause of death for people who died in the year ending June 1 of 1850, 1860, 1870, and 1880.
these schedules after 1880 were also destroyed when the other non-population schedules were destroyed in the fire at the Census Bureau.

National Archives and Records Administration - Genealogy

Library of Virginia - Genealogy Page

Church of Latter Day Saints - FamilySearch.org