The Scrum Primer is an in-depth introduction to the theory and practice of Scrum, and includes data on results from a large-scale corporate adoption of Scrum. Its authors are Certified Scrum Trainers Gabrielle Benefield, Pete Deemer, Craig Larman, and Bas Vodde.
You can download the Scrum Primer here.
Scrum Primer Creation
Scrum Primer was originally created by Pete Deemer and Gabrielle Benefield when they were both working in Yahoo! on their agile transition. When Craig Larman and Bas Vodde were working on their first Scaling Scrum book, they wanted to use a good introduction of Scrum as a reference but didn't want to write a new one. They joined forces with Pete and Gabrielle and all together rewrote the Scrum Primer.
The Scrum Primer 2.0 version was created for InfoQ and for being more consistent with the latest descriptions of Scrum.
What's a Scrum blog post without the a Scrum picture?
Here's a page thumbnail snip;
Based on the PDF document metadata, this guide looks very fresh, created 4/1/2013... [insert April Fools joke here]