Growth Hacker Marketing - Ryan Holiday's book, re-released and expanded
GrowthList - A crowd-sourced list of growth hacks
Your Growth Hacks Aren't Working - Free new book by Steli Efti on B2B customer acquisition
GrowthHackers Projects - Growth collaboration software for teams 📈
Spacedoo - Short actionable marketing hacks
Marketing Examples - A gallery of real world marketing case studies. Updated every day.