Tutorials:
Grasshoper Primer _ Lift Architects
Algorithmic Modeling by Mohamad Khabazi
Quick Grasshopper Intro at NJIT (Video)
Modelab Tutorials
digital toolbox
Usefull scripts and examples:
McNeel – Grasshopper Scripting Gallery
Pratt – Digital Futures Group
Flux Lift Architects
designrefom scripts+tutorials
Zesk grasshopper-scripting
Toolbox trier
Atelier nGai
Patched interwoven surface
LanCode