March 11, 2014
IRS Online Tax Filing
The deadline for online tax filing is midnight Monday night. You can learn all about the different types of online filing here: Free File: Do Your Federal Taxes for Free.
If you need a little extra help navigating the online filing system, there is a PDF file with full instructions here: Free Fillable Forms Tutorial
If that doesn't answer your questions, there is a Frequently Asked Question page with more information.