Association for Learning Technology Open Education Resources Special Interest Group (ALT OER SIG). This is a community, mainly based in UK higher education but with international contributions. It is one of the focal points for discussion of open practice in education — not just open educational resources — and you can follow or join in the discussion via its open mailing list, webinars, and community blog.
Open Education Handbook (2014), created as a project of the Education Working Group of the Open Knowledge Foundation, this aims to cover the area of open education quite comprehensively, with 47 sections each with links and pointers. This edition is hosted by Wikibooks, so if you see something you want to update, go ahead and click “Edit”.
Jisc guide to Open Educational Resources (revised version 2014) a guide for "senior managers, learning technologists, technical staff and educators interested in releasing OERs to the education community." and as such has an emphasis on institutional strategy.
Open Education: Fundamentals and Approaches (2017) a set of course materials for teaching staff, with five modules addressing different aspects of open education, created by a European project with partners including Coventry University.