A list that came out of a GOV.UK Product Manager community hour I facilitated recently.
Product Hunt (also, the Product Hunt browser extension)
About Face – the principles of interaction design
Simon Cross’s PM essential reading list
Ross Ferguson’s PM reading list
Design Museum’s Designs of the Year
Royal College of Arts, Show of the Year
Lectures, e.g. psychology
Formal guidance on the PM role and product lifecycle
DDaT skills they need – different levels of PM
Braun – 10 principles of good design
People to speak to
Other Product Managers
Other teams through internal show and tells
Other Product Managers on a shared task, e.g. working through 52 weeks of UX together.