I was just hunting around for the Sprint: How to Solve Big Problems and Test New Ideas in Just Five Days
by Jake Knapp, John Zeratsky, and Brad Kowitz
When I found these free materials on design sprints. Nice to see some easy to digest guides that I can make use of to advocate for the use of a define, decide, validate method of service or product development. There seems to be a bit too much focus on the decide part and not enough on the define and validate method in most organisations. You have to ask the right questions about the right problems or you are going to have troubles.
Design sprint methods: a playbook for start ups and designers [PDF 9.5 MB]
Design sprint - a methodology of structured brainstorming based on design thinking and agile development