GrowthHackList - 100+ curated growth hacks for makers + early stage startups
Growth Hacker Marketing - Ryan Holiday's book, re-released and expanded
Growth Hacking Sourcebook - The ultimate growth hacking sourcebook
Your Growth Hacks Aren't Working - Free new book by Steli Efti on B2B customer acquisition
Tiny Marketing Wins - Get a (small) marketing tip every day
Spacedoo - Short actionable marketing hacks