Startup School - How to start a startup, by Y Combinator
Bubi Chat - Location based anonymous chatting app
The Y Combinator Database - The definitive database of YC companies with all the metrics
HOLLA - Chatroulette for mobile
Apply to YC (Y Combinator) - Curated collection of resources for founders applying to YC.
Out of Office Hours - Connecting newcomers and people working in the tech industry