There's a good place to start. Just follow the rest of the Script Builder's Tutorials, and you will learn a little bit of RGSS. You pretty much have to experiment with stuff to see what it will do if you change a certain element or not.
As I recall, there's also a tutorial somewhere called RGSS for Dummies...
Here it is: http://digidog.createmybb.com/showthread.p...mp;pid=12#pid12
Not much, but it's something.