Some Web Resources for Free Online Filing of Income Taxes.
Many of the commercial tax software companies will let you prepare and file your taxes online for free. Many people don't realize this, and the software companies don't go out of their way to advertise it, becuase they'd rather charge you for preparation and filing services. It is somewhat confusing, and somewhat confusing to figure out how to take advantage of free online software for preparation and filing.
Here are some resources to help figure it out.
Free Online Filing
A good concise article explaining why many online commercial tax services offer free online filing for federal income tax returns, and explaining how to take advantage of it.
Your Link to Free Online Filing
The IRS's list of online companies providing free preparation and filing for federal income taxes. This page is more confusing than it should be. You're best bet is just clicking on the 'start now!' button. That will give you a list of websites, and what their requirements are for free usage. Note that some of the companies have income or other restrictions for their free services, but others do not.
TurboTax Tax Freedom
H&R Block - Free Online Tax Program
Well regarded industry leaders TurboTax and H&R Block both offer online tax preparation/filing for anyone, no income or other restrictions. Be careful, you need to go to these particular URLs (found on the IRS web page above) to use the free services. If you just go to these companies front pages, they'll happily charge you for the same thing you could get for free from another URL.
I have not found any commercial software businesses that offer free state preparation or filing. However, many state governments offer free filing services; some of them offer more help than others in preparing your tax return, but state income tax forms tend to be simpler than the federal forms.
Here is a site that offers links to state government websites from which you can get information about free online filing, if the state offers it.