Tax prep and electronic tax filing software

Government sites:

Free IRS e-file - Free online tax preparation and electronic filing services now available to at least 75% of all individual taxpayers. Other IRS e-file partners are listed as well.  
* If you need to, you can always file for an extension.  
State e-filing - More than 20 states now allow you to file your taxes directly through their websites for free!

Commercial filing sites: - Tax Act preparation software is free for basic returns, both state and federal. - Prepare tax returns with Microsoft Word downloadable forms. Most downloads are free.
     - Free for federal returns, state returns are extra -Turbo Tax software is free for taxpayers with adjusted gross incomes of $25,000 or less.       

Tax information sites: - tax help and info - tax help and info

The Volunteer Income Tax Assistance (VITA) program provides help to low- and moderate-income taxpayers. Call 1-800-906-9887 to locate the nearest VITA site.

The Tax Counseling for the Elderly (TCE) Program provides free tax help to people age 60 and older. As part of the IRS-sponsored TCE Program, AARP offers the Tax-Aide counseling program    at more than 7,000 sites nationwide during the filing season. To find an AARP Tax Aide site call 1-888-227-7669 or visit the AARP Web site.