By now there is a lot of good information available for CRM 2011 UR12 and the December 2012 Service Update. Here are links to some of my favorites:
-- 10 things I love about Dynamics CRM December 2012 Service Update
-- December 2012 Service Update and Update Rollup 12 – Important Information for Administrators
-- UR12 vs. Polaris: Commonalities Differences & Improvements
-- Easily Navigate through the Microsoft Dynamics CRM UR 12 (Polaris) Release
-- Announcing SDK Update V5.0.13 for Polaris and UR12
-- Preparing for the December 2012 Service Update and Update Rollup 12
-- Podcast and Overview: Microsoft Dynamics CRM 2011 Update Rollup 12 (of course)
-- Microsoft Dynamics CRM December 2012 Service Update Training Videos
Enjoy!
Ryan Anderson