Y Combinator Companies - Interactive list of all 1000+ YC companies
Startup School - How to start a startup, by Y Combinator
YC World - Explore Y Combinator companies by country
YC Interview Practice App - Get asked YC questions by Sam Altman
Unicorn Republic - List of startups that evolved into $1 billion+ corporations
Y-Combinator - Y Combinator provides seed funding for startups.