While most programming languages I've used are similar, MEL, Python, C, Javascript(back in the day for web) Using Javascript for Unity is pretty straight forward once you get the syntax.
For the most part I feel like I "got it" but reading over this in my spare time did solidify my foundation.
http://forum.unity3d.com/viewtopic.php?t=36096
and then this
http://www.unifycommunity.com/wiki/
I think going from MEL to Unity's Javascript with this thread is a leap forward, other than the more codey stuff later, it's a lot of the must know.
Javascript is a huge part of Unity, controls juuust about everything (or C#). So if you were a maya emitter/field tweak fx'er who didn't write a lot of functions to get your job done faster then this might not be a smooth transition.
Currenly I'm working my way through this long tutorial, taking my time to understand what we're doing.
http://unity3d.com/support/resources/tutorials/3d-platform-game
My only critique, if you can call it that, is there's a LOT skipped over in the name making it a doable tutorial (already 122 pages) They can't have you make EVERYTHING otherwise it'd take forever so they skip over a lot. That's cool, just leave big gaps to fill in later.