Quite some time back I had created a post related to the same topic, in which I had added a detailed list of courses and related resources. You might want to take a look at it here.
Some of the listings are as given below:
What is a Product Manager? Roles and Responsibilities
Behind Every Great Product - Marty Cagan
Four Key Product Principles from WeChat’s Creator
Develop Your Empathy and Create Better Products
Ryan Hoover on How to Develop Products People Love
You may go through the complete post and find a huge list to select from.
I hope it helps some of the aspiring PMs.