Y Combinator Companies - Interactive list of all 1000+ YC companies
Cyberleads - Find fast growing companies to do business with
Apply to YC (Y Combinator) - Curated collection of resources for founders applying to YC.
DollarLeads.co - A monthly subscription/one-off lead generation SaaS focused on driving quality over quantity on leads. All leads are hand-picked and focus on companies that are willing to hire/outsource parts of their operations.
Startup School - How to start a startup, by Y Combinator
SaasyDB - Lists of recently funded companies with verified employee email addresses, sent to you monthly