Design Kit is IDEO.org's platform to learn human-centered design, a creative approach to solving the world's most difficult problems. A useful resource with a number of books, guides, and free download, such as The Field Guide to Human-Centered Design.

Business Model & Value Proposition Canvas

A global standard used by millions of people in companies of all sizes
The Business Model Canvas is a strategic management and entrepreneurial tool. It allows you to describe, design, challenge, invent, and pivot your business model.
The Value Proposition Canvas helps you tackle the core challenges of every business — creating compelling products and services customers want to buy.

DIY Toolkit
 

Practical tools to trigger and support social innovation. The DIY Toolkit has been especially designed for development practitioners to invent, adopt or adapt ideas that can deliver better results. The free to download DIY toolkit is a collection of tools ranging from the Business Model Canvas to the Innovation Flowchart and Value Mapping.

Udacity: How to build a Startup
 

In an introduction to the basics of the famous Customer Development Process, Steve Blank provides insight into the key steps needed to build a successful startup.