Scrum Guide: The first place to start when thinking about adopting the Scrum framework
Scrum Guide
Scrum Mastery
Author: Geoff Watts
A fantastic book for Scrum Masters to start learning scrum or to refresh the practice of building high performing teams. From over a decade of Agile Coaching experience, learn Scrum Master best practices and how to implement them.
Essential Scrum: A Practical Guide to the Most Popular Agile Process
Author: Kenneth S. Rubin
A book that has use for all, this is a must read to get a clear understanding of Scrum.
Scrum: The Art of Doing Twice the Work in Half the Time
Author: Jeff Sutherland
A high level, easy to digest book on scrum that reflects on the last two decades of scrum, where it began and how it has developed in that time.
Scrum Alliance: Scrum Foundation eLearning
Product Owner in a Nutshell: Henrik Kniberg
A fantastic explanation of the Product Owner Role, an absolute must watch
Certification:
Scrum Alliance: Provider of the Certified Scrum training courses, Certified Scrum Master (CSM), Certified Scrum Product Owner (CSPO) to name the entry level. Also hold the Scrum Gathering annually.
Scrum.Org: Training provider of the Professional Scrum Training Courses. Professional Scrum Master (PSM) and Professional Scrum Product Owner (PSPO) for entry level. Once achieved, they are life long certifications.
Viking Agility 