Product School - The global leader in product management training
The Product Manifesto - Product Managers face the biggest challenges of our day, which is why our community needs a common set of product principles.
know/how Product Managers - A weekly newsletter with 5 practical tweet-length PM tips
Intercom on Product Management - The ultimate resource for aspiring product managers
Better Product Manager - Experience the life of a PM through these tests
PM Starter Pack - Practical guide on how to get started in product management