Content Marketing Stack - A curated directory of content marketing resources
Nawvel - Nawvel is a handy-dandy library of tried, tested & curated resources.
The Influencer Marketing Stack - Free resources to launch a killer campaign
Makerbook - A directory of the best free resources for creatives
Marketing Examples - A gallery of real world marketing case studies. Updated every day.
The Starter Kit - Curated resources for web developers and visual designers