In addition to various great TED talks (e.g. Designers — think big!, A call for "design thinking", How to build your creative confidence) our recommendations are:

• Creative Confidence, Tom & David Kelley
• The Art of Innovation, Tom Kelley and Jonathan Littmann
• The Ten Faces of Innovation, Tom Kelley
• Game storming, a playbook for Innovators, Rulebreakers, and Changemakers, D. Gray, S. Brown, J. Macanufo
• Road Trip to Innovation, Delia Dumitrescu
• Design-Driven Innovation - Changing the Rules of Competition by radically Innovation What Things mean, Richard Verganti
• Human-Centered Design Toolkit, IDEO
• Democratizing Innovation, Eric von Hippel
• What matters now, Gary Hamel
• To Do: Die neue Rolle der Gestaltung in einer veränderten Welt, Florian Pfeffer
• Design Thinking, Innovation lernen - Ideenwelten öffnen, Hasso Plattner, Christoph Meinel, Ulrich Weinberg
• Durch die Decke denken, Jürgen Erbeldinger, Thomas Ramge
• A Whole New Mind - Why Right-Brainers Will Rule The Future, Dan Pink
• Change by Design - How Design Thinking Transforms Organizations and Inspires Innovation, Tim Brown
• The design of Business: Why Design Thinking is the next competitive advantage, Roger Martin
• Rapid Viz, a new method for the rapid visualization of Ideas, Hanks & Belliston
• The back of the napkin, Dan Roam
• Visual Meetings, David Sibbet
• Visual Leaders, David Sibbet

• Visual Teams, David Sibbet
• Business Model Generation, Alexander Osterwalder & Yves Pigneur
• Improvisation and the theatre, Impro for storytellers ,Keith Johnstone
• Motivation und Persönlichkeit, Julius Kuhl
• Leadership Embodiment: How the Way We Sit and Stand Can Change the Way We Think and Speak, Wendy Palmer, Janet Crawford
• Embodiment and the inner life: Cognition and Consciousness in the Space of Possible Minds,Murray Shanahan

Digital resources

• d. school Stanford - Bootcamp Bootleg
• The virtual crash course Playbook, d.school Stanford 
• IDEO Method Cards
• Stanford University - Foresight and Innovation
• Business Model Canvas - Osterwalder / Pigneur
• Value Proposition Canvas
• Design Thinking Method Cards, University of St. Gallen
• Jakob Nielsen, Principal at Nielsen Norman Group
• The ROI of User Experience
• Design Kit
• Resources I Design Council
• Design Management Institute
• http://ddc.dk/en/2015/05/the-design-ladder-four-steps-of-design-use/
• DMI, the four Powers of Design
• http://www.keithjohnstone.com/
• http://www.thewayofimprovisation.com/
• Games and exercises in improvisation
• Ted Talk: Dave Morris – The Way of Improvisation
• Steve Matuszak - The Art of Improvisation
• Zach Beattie - The Art of Improvisation