In the United States in 2011, more than one in four people were going to school. This included many types of people—children going to nursery school and elementary school, young adults attending high school and college, and adults taking classes to obtain a degree or diploma. What do we know about these people—their age and sex, where they live, their progress through school, the types of schools they attend? This report provides a guide to data from the U.S. Census Bureau and other sources that provide a picture of the 83 million people who are enrolled in school.