The Demographic Transition
From your About.com Guide, an overview of the stages and their causes.

Doubling Time and Population Growth
Growth rates and doubling times are fascinating demographic variables that are used to estimate a country's future population.

Animated Population Pyramid
This animated population pyramid for the United States vividly display the aging of the population from 1950-2050 in 5-year increments.

Glossary of Population Terms
An excellent glossary from the Population Reference Bureau - explains key principles of population and demographics.

Animated Population Pyramids
Nine animated population pyramids showing 1950-2050 projections. Includes the world, more and less developed regions, Europe and Africa, and as examples, Italy and Uganda.

Myth of the Melting Pot: America's Racial and Ethnic Divides
A fascinating Washington Post article about the latest wave of immigration to the U.S. from Asia and Latin America.

U.S. Sex Ratios
An animated map of the U.S. showing the sex ratio of men to women in the each of the lower 48 states from 1790-1990.

Who is Missed by a National Census?
An academic study of census results from Australia, Britain, Canada, and the USA that discusses the proportion of the population missed and what can be don about an undercount.