Startup School - How to start a startup, by Y Combinator
The Y Combinator Database - The definitive database of YC companies with all the metrics
Electron Toolkit - Toolkit to build and launch Electron apps
Apply to YC (Y Combinator) - Curated collection of resources for founders applying to YC.
Rippling - One directory for employee information across IT, HR, legal, finance and facilities.
Officehours - Connects you with amazing people, for one on one advice