How do we prevent this from happening again?
Education and more government regulation. The Dodd-Frank Wall Street Reform and Consumer Protection Act was enacted in July 2010 with the intent to fix what was broken and to prevent a similar crisis.
The New Financial Deal by Books published on this topic will continue to grow, but here are a few to get you started reading.
Regulating Wall Street by 
American Public Media has an RSS feed dedicated to the crisis. Check the feed out or hop to their website.
Wondering how your Representative voted on the stimulus money? Was this a partisan statement?
Use the following links to research the law and implications of the legislation.