Links
Websites
https://modernagile.org/ - the home of Modern Agile
https://retromat.org/en/ - an awesome retrospective planner & guide
https://www.scrum.org/ - the home of Scrum
https://www.scrumguides.org/index.html - the Scrum Guide, in various formats
Books
Agile Retrospectives
Not just what retrospectives are, but how to do them and why they work. The tome on the topic.
Coaching Agile Teams
A Companion for Scrum Masters, Agile Coaches, and Project Managers in Transition. The definitive guide, full stop.
Rolling Rocks Downhill
Accelerate Agile using Goldratt's TOC - a business novel that explains the Theory of Constraints much better than any textbook.
The Bottleneck Rules
How To Get More Done at Work, Without Working Harder. A fantastic, easy, informative read.
The Lean Startup
Eric Ries' seminal book on how to figure out not just what to do, but also how - and in what order. It's legendary for a reason!
The Phoenix Project
A cleverly written and very approachable "business novel" that reveals, step by step, how even insurmountable-seeming problems can be solved by application of sound process. A great intro for DevOps.