AMA Model Aviation - Official Magazine of the Academy of Model Aeronautics.
AMA Sport Aviator - Good resource for new pilots.
Checkout the Sure-Start-Guide and First Steps.
Model Airplane News - Main site for several magazines related to Model Airplane News.
Check out the weekly Radio Control Show videos. Also, they have an app for that.
Fly RC - Training, "Wing Tips", Reviews, Flight Reports, Plans and more...