Mike Cohn: https://www.mountaingoatsoftware.com/blog
Roman Pichler: https://www.romanpichler.com/blog/
Allan Kelly: https://www.allankelly.net/
List of useful templates and tools from Chris Stone: link
Product - multiple useful links from Pawel: link
Infographics and software craftsmanship-cards from Yoan T.: link-books and link-cards