Intercom on Product Management - The ultimate resource for aspiring product managers
Product School - The global leader in product management training
userinput.io - Get on-demand feedback for your app, website or idea. Learn how to improve by hearing real opinions.
The Product Folks - A volunteer-led community of product managers and makers
ithinki - A simple user feedback tool for start-ups
Software Product Management Stack - Resources & tools to help you manage your software product