FaxZero provides two free online faxes each day. Infrequent faxers don't need anything more to send free faxes from their computers.
Simply save a Word document you want to fax on your computer.
Enter your name & email address to receive the confirmation emails from the online fax service.
Then provide the fax number and company information, upload and send the file; kind of like sending an email.
You will receive fax confirmations in your email inbox within 20 minutes if the fax was sent successfully.
See http://faxzero.com/ to start. Very simple to send an online fax using your computer.