I picked it up pretty quick. But I've been programming since 1981 (in Fortran IV)
I use the RGSS help that comes with RMXP, and the official Ruby sites www.ruby-lang.org & www.ruby-doc.org
You can read the entire RMXP help doc in one sitting. It may not all make sense right now, but you'll be aware of everything that's there.
But mostly I just studied the default scripts until I understood how they worked.
There are a few listed here:http://www.hbgames.org/forums/viewtopic.php?f=48&t=1868
The other major RPG Maker support sites (Creation Asylum, Chaos Project, RMXP Unlimited, etc..) have tutorials & support as well