I'm going to plug a document myself and a bunch of other community members worked on:
https://github.com/MC42/FRCPenultimateManual
The gist of it is as follows:
Read and watch Karthik's talks.
Talk to older teams!
DON'T JUST DO TEAM STUFF DURING THE SEASON! Robot season may end but robot year is 365.25!
Good luck!