DigitalSignup.net - Digital Signup is an easy-to-use class registration software that facilitates community education programs, childcare, preschool, and hospital programs.
Startup School - How to start a startup, by Y Combinator
Registrar Registry Manager - Advanced Registry Manager for Windows
The Y Combinator Database - The definitive database of YC companies with all the metrics
Out of Office Hours - Connecting newcomers and people working in the tech industry
Apply to YC (Y Combinator) - Curated collection of resources for founders applying to YC.