I’m a big fan of product discovery, and this extensive guide from Tim Herbig is a great resource:

The goal of this guide is to show you the extensive range a Product Discovery can have and how to set up and execute your own Product Discovery process. Which exact phases, tools, frameworks, and participants are needed depends on many individual aspects like the maturity of your product, which stakeholder environment you’re operating in, which resources you have at hand, etc.

I also like his definition a lot:

Product discovery is about ensuring that the right product gets built for the right audience. It’s the foundation for a successful implementation and launch phase later on and should give you the confidence to represent your product vision towards your team and stakeholders.

This is a guide I will return to again and again for inspiration.