I strongly recommend cindy alvarez' "lean customer development" which is spot on: http://www.amazon.de/Lean-Customer-Development-Building-Customers/dp/144935635

I strongly recommend cindy alvarez' "lean customer development" which is spot on: http://www.amazon.de/Lean-Customer-Development-Building-Customers/dp/1449356354 http://www.amazon.de/Lean-Customer-Development-Building-Cust... ... In fact the lessons learned from this book are invaluable I'd say. If you want to be serious about product design for endusers, read this. When doing the UI/X later, this book helps a lot: http://www.amazon.de/Dont-Make-Think-Revisited-Usability-ebook/dp/B00HJUBRPG/ref=sr_1_1?s=books-intl-de&ie=UTF8&qid=1436568356&sr=1-1&keywords=Dont+make+me+think http://www.amazon.de/Dont-Make-Think-Revisited-Usability-ebo...