Product School - The global leader in product management training
Maze Templates - A library of pre-made user tests and surveys
The Product Manifesto - Product Managers face the biggest challenges of our day, which is why our community needs a common set of product principles.
UserTesting.com - Usability testing has never been easier. Get videos of real people speaking their thoughts as they use websites, mobile apps, prototypes and more!
Intercom on Product Management - The ultimate resource for aspiring product managers
Marvel - Turn sketches, mockups and designs into web, iPhone, iOS, Android and Apple Watch app prototypes.