Information and resources useful to mentors and coaches can be found here.
FTC Robotics: Tips, Tricks, Strategies, and Secrets
The Pope John XXIII Regional High School Robotics Team wrote this great book which is a collection of FTC tips, tricks, strategies, and secrets they have collected through their experiences as well as from other FTC teams. I recently purchased a copy of this book and it is a great resource for both veteran and rookie teams. The book is available through Amazon here: Link for purchase of FTC Robotics: Tips, Tricks, Strategies, and Secrets