Nobody ever mentions source code.
The way most scripters start up is by them messing around with code and realizing how much they really like it or something like that.
I got into scripting because I GM'd on another server and the admin hired me as a debugger. I already had a fairly good grasp on how coding should look, so I went ahead and went through all the NPCs/quests/etc to debug them (clean up errors, like typos and messed up numbers) for them to work better.
Bug the support forums at eAthena or ask around here. I'll even hook you up with some good tips on coding and maybe even teach you how to make your own NPCs.
I know for a fact heRO is in need of people to test things out, but I also know the GMs LOVE hosting events, so why not give them a few scripted ones for their enjoyment? :3
PS: I like working with people, so if you're interested, PM me. xD