Make sure your webhost is capable of providing accurate time information for PHP/WordPress, ie. make sure a NTP daemon is running on the server.
Install and activate the plugin.
Enter a description on the Users -> Profile and Personal options page, in the Google Authenticator section.
Scan the generated QR code with your phone, or enter the secret manually, remember to pick the time based one.
You may also want to write down the secret on a piece of paper and store it in a safe place.
Remember to hit the Update profile button at the bottom of the page before leaving the Personal options page.
That's it, your WordPress blog is now a little more secure.
Requires: 3.8 or higher Compatible up to: 3.8.1 Last Updated: 2014-2-11 Downloads: 39,617