To begin your research, think about where you are in the inquiry process.
 Gale American History In Context
Facts on File: American History
Try a smart keyword search that best fits your topic.
Brown v. Board of Education
Jim Crow Laws
Little Rock Nine
Civil Rights Act of 1957
Woolworth's Lunch Counter (Greensboro Sit-ins)
Selma to Montgomery March
March on Washington
The Library of Congress' American Memory Project provides some interesting primary sources that might help your research.
Try searching for your topic. You are looking for short video clips that feature footage of the actual events.
Primary sources include:
Newsreel footage
Photographs of the actual events