Read Time, Nobel Laureate: How to Get Out of the Financial Crisis. Joseph Stiglitz writes that the "troubles we now face were caused largely by the combination of deregulation and low interest rates . . . [ l] oose money and light regulation were a toxic mixture." He suggests that we recapitalize banks, stem the tide of foreclosures, pass a stimulus that works, restore confidence through regulatory reform, and create an effective multilateral agency.
Also read Washington Post, We Forgot Everything Keynes Taught Us.
And if you are interested in more details, see The Baseline Scenario, Financial Crisis for Beginners.
Or play an updated version of the Depression-era board game Monopoly, Econoply, with loose money, instant mortgages, vague and constantly-changing rules, and Bankers that can't go bankrupt.