Startup School - How to start a startup, by Y Combinator
Owlead - Grow your Twitter with valuable followers, effortless
Hyper Founder Program - An 8-week founder program inspired by Product Hunt
BaseTemplates - The easiest way to build your pitchdeck and raise money
Indie Hackers - Connect with fellow entrepreneurs, developers, and bootstrappers who are sharing the strategies and revenue numbers behind their companies.
Lambda School - A full Computer Science education - free until you get a job