A great summary that matches my perspective and the structures that I implement for Product teams.
product_management
The Product Lexicon (v2)
Handy set of definitions for common terms in Product Management.
Product management templates
Agile and the Long Crisis of Software
Product Management Kanban Board
Ramen
“Ramen is the best way for SaaS Product Teams to learn about their customers, ask those customers questions, and discuss features and ideas with them.”