Another great resource, sadly not centrally indexed anywhere: Julia Keren-Detar’s talk on designing video game tutorials.
What’s particularly striking to me about this situation is that this talk isn’t hosted on the GDC website, or DiGRA’s, or at any other location where one commonly goes for this sort of discussion. One has to know it exists to find it. That’s clearly not OK; we really need a better clearinghouse for industry knowledge!