Good news: A lot of people can prepare and eFile (federal and state) taxes for free on (the desktop software charges you to eFile state returns). You can also download your tax return in the format that the TurboTax desktop software uses. Bad news: You can't upload/import documents (such as a return you'd already started in the TurboTax desktop software) into your free account. You also have to create a separate account for each person that's filing their taxes; you can't simply use your personal account to file taxes on behalf of family members.
Something I learned last year: if you use the calculator to figure out how much to claim for donated furniture, do a screen shot of the list, because the list is not included in the final paperwork you get. I wish I'd thought of that at the time. ‎- bentley