Hey, there is a new Rhino-related course at Lynda.com and I didn’t do it! Even so, I found it excellent. This one was written by Chris Reilly and he really know his stuff.
Grasshopper—a plugin for the Rhinoceros 3D modeling package—is a graphical algorithm editor that takes advantage of Rhino’s existing tools. Grasshopper offers new ways to expand and control the 3D design and modeling processes, including automating repetitive processes; generating geometry through mathematical functions; quickly making changes to complex models; and creating complex forms through repetitions of simple geometry.