We don’t have much time until the United States runs up against the federal debt ceiling.
Here are a few related resources that might be useful (you might also be interested in The Best Resources To Help Understand The Federal Government Shutdown):
The Associated Press has a short video.
Interactive | Debt Ceiling 101: A look at the nation’s balance sheet
What’s up with the debt ceiling? is a CNN slideshow.
A recent history of America’s debt ceiling, in one interactive graphic is from The Washington Post.
History lesson: Why did Congress create a national debt limit? is from The Washington Post.
Everyone The U.S. Government Owes Money To, In One Graph is from NPR.
Foreign Holdings Of U.S. Debt is a Washington Post infographic.
Republicans and Obama in debt crisis talks is a Breaking News English lesson.
I would highly recommend looking at recent Congressional Research Service reports (made for Congress) on the Debt Ceiling:
The Debt Limit: History and Recent Increases: http://www.fas.org/sgp/crs/misc/RL31967.pdf
Reaching the Debt Limit: Background and Potential Effects on Government Operations:
http://www.fas.org/sgp/crs/misc/R41633.pdf
Votes on Measures to Adjust the Statutory Debt Limit, 1978 to Present:
http://www.fas.org/sgp/crs/misc/R41814.pdf