I know this is going to be a really noobie question that I'm asking, but does anyone have a nice 'free' site, article, online book, or collection of tutorials on how someone can begin to learn some Lua coding for use a little bit later on in life. Why am I doing this? I want to make a nice fully customized server in Half Life 2's mod of Garry's Mod 10... I love playing that game and I am soon going to be learning Lua in college but I figured that why can't I get a head start on some things? Any help is well appreciated!!

Learn it in Gmod and off their forums.
Seriously, that's how I got a basic grip on Lua, it's a good start, especially if you plan on taking a proper course later.

I learned lua in about a week and mastered gmod's stupid variation of it in a month. But then again, I've already had programming experience with other languages, so that timeline might not apply to you.

How would I learn it in GMod? I will go check out the GMod forums to see what they offer me but I don't see how I could learn this by playing in GMod...

Mess around with other peoples scripts, figure out what they do. Be creative, make something from scratch, or change something til it looks good.

Use google to find a tutorial. Something as simple as "Tutorial Gmod Lua". Make some basic scripts and test them out in Gmod as you go through the Tutorial. Don't just read the tutorial, make scripts while reading the tutorial, that way you get hands on experience.