The Y Combinator Database - The definitive database of YC companies with all the metrics
Creddon - Tweet for a cause and a sponsor will donate $1 to charity
Startup School - How to start a startup, by Y Combinator
Wheelys Dreams - Crowdfunding for making dreams become real
Apply to YC (Y Combinator) - Curated collection of resources for founders applying to YC.
UpEffect - Crowdfunding for social good products