How to Start and Organize a VEX Robotics Team This refers specifically to an older game but everything else is good.
Software RobotC You have to have an account at vexrobotics.com to download.
Communicate and Collaborate with the VEX community through the VEX FORUM
Equipment can be found at vexrobotics.com. See game rules for what can and cannot be used.
VEX Inventor's guide is available in PDF form here. Scroll down to the bottom of the page for the PDF downloads. This Inventor’s Guide is provided as a tool to help you get accustomed to all the features and functionality of the VEX Robotics Design System. Included in this guide are various chapters which detail the individual subsystems involved in a basic robot. Each chapter includes a description of the components used, the concepts involved in designing and building the subsystem, and how the subsystem interacts with other subsystems.
101 Things you Should Know Before Your First VEX Tournament
Nice video of an actual competition
Very cool actual competition in China
Not as good as the one from China, but interesting.