I love the idea of FIRST-specific training, and I think there will also be an ongoing variety of general robotics training and courses available online. Just yesterday, I found this awesome-looking intro to mobile robotics offered on Coursera starting July 4:
https://www.coursera.org/learn/mobile-robot#
For those non-FIRST-specific robotics courses, it would be great to just have one place to go where the list of resources is crowd-sourced.