Ask HN: Courses and essential readings for Agile project mgmt?

I work at a fully remote software company and I'm looking for resources to add to our onboarding course for freshly hired developers. The topics I'm looking for can be anything along the lines of Agile project management, epic management, and time management. We don't have dedicated project managers - project mgmt tasks are distributed among the development team (who work in small, self-managed "cells"). I want to familiarize new hires to the principles of Agile project management and am looking for "essential" courses or readings on the topic. Anything you can recommend or would like to share? Many thanks!