Startup Toolkit - Interactive how-to guides to launch your startup
Checklist Design - The best UI and UX practices for production ready design.
Techstars Entrepreneur's Toolkit - Online resource to help you learn about entrepreneurship
Design Principles - An open source repository of design principles and methods
AwesomeHunt - Community-curated lists of learning resources on any topic.
The modern web design process - An in-depth guide to the processes behind great websites.