Self-Employed Workers

• If you work as a contractor outside of a traditional employment situation, you owe taxes on all self-employment revenue. Although each client who paid you $600 or more in the year must file a 1099-MISC reporting that income -- you receive these in the mail around the end of January -- you must report all income. If you earned $400 or more through the year, you must pay self-employment taxes -- 15.3 percent for income earned in 2010 and 13.3 for income earned in 2011 -- on your earnings. In addition, this income is taxed at your normal income tax rate.
  
  

Unemployment Benefits

• If you received unemployment assistance any time in the tax year, expect to pay taxes on it. The IRS considers all unemployment benefits taxable income, and the state agency that paid your benefits will file a 1099-G reporting the amount of support you received. You must pay income taxes on this money at rates determined by your tax bracket.
  
  

Pensions and Annuities

• Many pension plans and annuity payments are treated as taxable income. You may submit a W-4 form to the fund manager to withhold taxes throughout the year similar to payroll withholding, or pay your tax bill at the end of the year. Some Social Security and equivalent railroad pension plan benefits may qualify for taxation. If your taxable income from dividends interest and other pensions plus half your Social Security pension is larger than $25,000 if filing individually or $32,000 if filing jointly, you'll be required to pay taxes on those benefits as well.
  
  

Interest and Dividends

• Interest on savings and checking accounts, money market accounts, insurance dividends and U.S. bonds that have matured must be reported to the IRS as income. Dividends paid to stockholders are also taxable income and must be reported on your taxes if you receive them.
  
  

Capital Gains

• If you weren't employed but sold a large asset, such as property, stocks or another appreciating asset, you may need to report this income on your Form 1040. If you sold the asset at a profit -- anything more than the price for which you purchased it -- the IRS treats this revenue as capital gains. Most capital gains are taxed at 15 percent, which is usually lower than other forms of income. If you earned little other money throughout the year, your capital gains tax rates may be reduced to 0 percent.