www.tourdivide.org 
"Official" site for the Tour Divide race - as underground as the race this site has not been updated - but is a great resource to start out your planning

www.facebook.com/tourdivide2015
My Facebook social group - I will be building out this site as I go along - but instead of spamming everyone with crazy biking updates I will share here with the specialist group.

www.facebook.com/groups/ultraride
Probably one of the most valuable groups on Facebook with a collection of characters who are defining the sport of  bikepacking. Scott owns this group and road the Tour Divide in 2013 - and wrote a book "Trail Magic" 

normallyaspiratedhuman.com
Mike Hall (TD '13 Winner) and general ultra Adventurer. Mike is a great inspiration and has many useful articles - and some great stories