Yahoo Market Watch Article: Big Tax Mines That Could Blow Up Your Return
"The payroll tax cut" is the thing on this list I'm guessing will effect the most of us.
Here's how the IRS explains it: Payroll Tax Cut Temporarily Extended into 2012
If your paycheck mysteriously shrunk a bit earlier this month, then pops back with a little extra, this could be the culprit. This continuation of the 2% tax cut from last year will only extend until Febuary (unless they decide to extend it further). If you make over $18,350 in January/Febuary, you'll be paying some additional taxes for this two month period, but since that means you're making over $110,000 per year, I think you'll be okay.
Same advice as previously, this 2% is coming out of your social security payment....you know that fund they're already predicting will be exhausted by 2037. So I'd take that 2% and put it in some form of retirement savings.
(Dave Ramsey suggests 15% would be ideal, but doing what you can is definitely better than doing nothing.)