The dummy’s guide to gathering qualitative or quantitative feedback in order to inform product vision/feature decisions

Many people are asking:

Where is the dummy's guide to gathering qualitative or quantitative feedback in order to inform product vision/feature decisions?

Noted internet luminary J.P. Rainsberger, for example has asked:

And it can certainly be a challenge to get started on such a daunting task.

One great place to start is the work of Amy Hoy and Alex Hillman around "Sales Safari" and I urge you to dive deep into their work. They've put a video online showing an earlier version of their sales safari lesson.

Another place where this will be covered in more detail is the book I am hastily throwing together, which spends quite a bit on the mechanics (and pitfalls!) of qualitative research, as well as pointers on quantifying your findings.