The NY Times has an excellent collection of essays that discusses U.S. presidents and their debts. Richard Reeves' "Reagan's Deficit Dreamscape" is wonderfully written, easy to understand and, more importantly, reminds everyone that Reagan started the "borrow and spend" policies that have put us in a hole today. But my favorite is David Kennedy's "FDR, Budget Hawk." It's short, to the point, and dispels any notion that conservatives have about FDR being a spend thrift.
They're all excellent, so I hope you can find the time to read some of them.