American-Historama for Kids: Financial Crisis (NEW 2019):
American History for Kids: The Great Recession 2007-2009
The Balance: The 2008 Financial Crisis - Overview
Britannica: Financial Crisis of 2008
Crash Course History VIDEO: The 2008 Financial Crisis
History.com: The Great Recession
Positive Money: Financial Crisis & Recessions (uses the UK as an example, but simple explanation)
These overviews will help you understand what the Financial Crisis affected, and how.
Crash Course History VIDEO: Money & Debt
VIDEO CHANNEL: Crash Course History Economics (35 amazing videos!)