These FIRST Robotics Team sites are filled with great reference materials.

Team 27-Team Rush
http://www.teamrush27.net/parent-resources
A set of resources compiled by a veteran team.

Team 234-Cyber Blue
http://cyberblue234.com/
Creator of clickFRC.

Team 365-MOE University
http://moe365.org
A set of courses hosted by MOE mentors to educate members.

Team 1114-Simbiotics
http://www.simbotics.org/resources/app
A great tool for information on several different robotics topics.

Other Helpful Links:

NEMO – Non-Engineering Mentor Organization This website shares papers, presentations, and stories about the non-technical aspects of team management.