How to begin creating mods for new games, as a beginner?

[GankThat]

There's a lot of resources here I will read when I have more time but I was just curious, how do mod authors go about determining just how to mod games when they're new?

Do they rely on mod kits or do enterprising authors literally go into the source code and figure it out?

I have an idea for a mod for Skull and Bones that seems like a simple mod to write but I have never done it.  I am I'd say moderately adept at coding, so I'm not sure if this is even something I'll understand.

So other than "search the forum for your topic" does anyone have any advice on writing mods for brand new games, maybe especially from the perspective of a prospect developer?

 

Thanks everyone