Normally I don't like to just put in links to other blogs since you can read that stuff by clicking on my links to those blogs. But since the economy is in the news so much and since alot of that is on what caused the crisis and what needs to be done, these two links are important in giving a different perspective.
The first one is What Really Happened? by Larry White of the University of Missouri. He blames the FED keeping interest rates too low for too long and there being too many "sub prime" loans, that is, loans with lower standards for incomes of the borrowers and downpayments. The government encouraged these home loans. Adjustable rate mortgages play a role, too.
Then there is Fiscal Policy Puzzles where Harvard professor Greg Mankiw disucsses the fact that fiscal policy might not work the way we want it to. That is, increasing government spending might not help very much (although he says " I am not sure what model I should use to explain" this). He also says "At the very least, these puzzles should give us reason to pause when using the Keynesian framework for policy analysis. There is still a lot about macroeconomics that remains deeply puzzling."
Another post by Mankiw is The Bils-Klenow Stimulus Plan. This suggests that cutting payroll taxes (social security taxes) is the best stimulus.