ToME: the Tales of Maj'Eyal

So, I'm completely new at this, so this might be a dumb question/already answered somewhere; but how does one go about actually creating addons? I've wanted to try my hand at it for some time and I have no clue where to begin.

1, get a hold of "SciTE - a scintilla based text editor". (at least that's what i have, not sure if another thing would work)
2, be sure you know how to edit text file extensions (bits after the dot)
3, read the tutorial on the wiki.
4, get a random addon, and dissect it.

if your system doesn't show them by default, go to.
-organise (expends downwards a list of options)
-folder and search functions
-view (second tab)
-in advanced settings, find "hide extensions for known file type".
this bugger kept me from starting for months.

also, something like winrar is useful, if you don't want to decompress and re-compress the whole thing every time you want to adjust a number.

IMO, learn how to use a good text editor like Atom, learn a bit of Lua and then dissect an addon, like Radon said. The wiki does help, but I mainly used it for list of callbacks and explanation of hooks.