The Ducksters website is an educational site especially for kids and is a great source of introductory information for a topic. You can also opt to have the page read aloud to you, and do a quick quiz to check your understanding.
TED-Ed 2015. The incredible history of China's terracotta warriors. Online video, 30 June 2015. Duration: 5 mins.
The Qin Dynasty - The Age of Unification. 2012. Online video, 18 September 2012. Duration: 3 mins.