Product Management Exercises - A repository of product manager job interview exercises
productboard - Beautiful and powerful product management.
PM News - The best product career advice —from world-class PMs.
ProdPad - ProdPad helps your team gather ideas, surface the best ones and turn them into product specs, and then put it all on a product roadmap.
Interviewlab - Stop wasting your time searching job interview questions
ProductPlan - Cloud-based product roadmap software solution