Intro to Product Management?

I am currently heading a project in my company where we are going to develop a product that is fairly new for us, for a market we're not yet in. The goal is to develop a web app - some parts we can take from earlier developments, others will have to be adapted or made completely new.

I'm experienced with project management but I'm new to product management. I'm sometimes feeling like a complete newbie when I'm talking to my product manager, so I was wondering whether any of you know an introduction to product management?

I just want to know what I'm talking about - so I was thinking anything that takes between 1-3 hours of introduction; no matter if it's a video, ebook, articles etc.?

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