After you finish entering all of your information, you have to review and file the return before you are done. And as long as you are getting a refund, there are no penalties. If you owe, you have to pay before 04/15 to avoid any penalties.
It's easy to e-file your return. Simply finish your tax return, select File in the left menu, and follow the instructions until you can select the Transmit my returns now button. You must select that button to electronically send your return to the government.
Once you've done that, the next thing you should see is a Transmission Successful screen. This means your return is on its way to the government agency.
Your e-filed return will remain in pending status until the government either accepts or rejects it. Once it is accepted.