I obviously know how to make the effects, and other things. But the one kind of mod I don't know how to make are the mods like @wondible makes. These are of course made with years of experience, I can see this when looking at the .js things. Obviously you can't become an expert by reading or watching a single guide for a mod. The kind of thing that I and other people that might want to see in a guide/tutorial is an explanation of the code, like what does X do with the mod. I think examples are the best way to learn anything. I've been using codecademy to learn stuff so far, I'm still at the very basics, I at about 50% done with JavaScript and 40% done HTML and CSS. If a video is made, I'll vote for it on the contest page and make multiple accounts to make sure it wins
I tend to document things when I'm answering the same questions over and over again. There aren't currently a lot of people trying to do this, especially in sufficient local concentration to make it seem like an urgent need. Having specific questions would help. Perhaps there could be an occasional event a-la pendulum of war. Challenge for me: The computer where I'm set up for development can only stream with difficulty, particularly when running PA at the same time.
I plan to make a modding orientation video, which would be little more than explaining scenes, how to do things like shadowing stuff and adding to functions, the format of a mod, and where the basic api is (aka stuff you probably know already). Beyond that, I'd watch a stream/video of someone talking techy techy. I can follow things like the instant sandbox code, but writing something as polished as that is a different ball game. Maybe someone could take one of their mods that touches on a number of things, and goes through it pointing out what api he is using here, why he is doing X in this way there (instead of what might be a more naive approach), etc. Something that will help is learning the basics of knockout, some UI stuff doesn't make a lot of sense until you figure it out. Also, underscore and jquery (any more core libraries?), and familiarising yourself with the game api. The more you know about everything the quicker you can understand and use it; but even just a little knowledge of where to look stuff up is enough to decipher what is going on with someone else's code, with enough patience and coffee