A bit of self-promotion: this article I co-wrote covers both OAuth and OIDC: https://fusionauth.io/articles/oauth/modern-guide-to-oauth

I particularly like the idea of "modes" which discusses different ways of thinking about authentication and authorization based on who holds user data.

HN discussion here: https://news.ycombinator.com/item?id=29752918

Edit: updated link to HN discussion