In this interesting article from CIO.com, Michael Hugos talks discusses the best practices surrounding Agile development's 30-Day Blitz, and the important of the Define step.
"Remember that most problems and situations seem complex at first but don’t be fooled by the surface complexity. Many business problems, regardless of their details and differences, can be effectively addressed by systems with a common design pattern."
Agile Development, Project Management and Step 1 of 3 by Michael Hugos
Succeeding with Agile: Software Development Using Scrum ~ Mike Cohn
Clean Code: A Handbook of Agile Software Craftsmanship ~ Dean Wampler
User Stories Applied: For Agile Software Development ~ Mike Cohn