Tribe of Mentors - Short life advice from the best in the world, by Tim Ferriss
Startup Fucking Advice - A humor-based website that gives random startup advice.
MentorCruise - Personalized mentorship experiences
Great F*cking Startup Advice - Strongly worded suggestions for startup founders
Frontend Mentor - Supercharge your front-end skills by building in a real-life workflow. Solve real-world HTML, CSS and JavaScript challenges whilst working to professional quality designs.
Startup Notes - Most actionable advice from each Startup School speaker