Check it out at http://ccss2016.tumblr.com
There, you will fine a tentative timeline of the Secret Santa as well as the rules laid out on how to submit prompts as well as the process of getting your SS.
You can participate even if you don't have a Tumblr, as assignments are sent out via email.
Note: When submitting your email, either put brackets around yahoo[.]com or spell out the dot com or Tumblr will eat your submission.
Prompts are due by EOD on December 5th. (Sorry for the late notification.)
On a personal note, this is my first Secret Santa.