Mentory - On demand career mentors to succeed at work.
Software Product Management Stack - Resources & tools to help you manage your software product
Tribe of Mentors - Short life advice from the best in the world, by Tim Ferriss
The Product Management guide - A book on how to create and ship products that people love
MentSpot - Find a mentor or become one for free
Product Management Exercises - A repository of product manager job interview exercises