Growth Hacker Marketing - Ryan Holiday's book, re-released and expanded
Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.
Top of the Lyne - Growth strategies and the weekly news from the best product-led SaaS companies (Figma, Calendly, Notion, and more) for founders and growth leaders!
HTMLEmail.io - Responsive HTML email templates for startups & developers
GrowthHackList - 100+ curated growth hacks for makers + early stage startups
Startup Emails - Responsive HTML email templates for startups