Startup Toolkit - Interactive how-to guides to launch your startup
Hunter TechLookup - Create lists of websites by technology for free
Toolbird - Discover online tools that other startups use
Techmap.io - Techmap is a workplace search engine to find companies using technologies (e.g., Rails, PHP, Java, etc.) that are used internally. Finally, a "Google for Workplaces" that helps people find a place to work with technologies they love!
Techstars Entrepreneur's Toolkit - Online resource to help you learn about entrepreneurship
Setalist - The easiest way to make awesome lists for the internet