Has anyone written a biography or non-fiction novel about a family member? How did you navigate it?

After many, many years of thinking about this project, I'm embarking on writing a book about my father and his side of the family. It's roughly a biography and family history, but it's also a little bit of a memoir for myself. I was wondering if any non-fiction writers here have ever written about a family member (especially a parent) before, and what the process was like. My dad will be collaborating with the project. He has done some fascinating, amazing, and also insane things in his life, intersected with large portions of U.S. history, is the keeper of our family history, and he has a lot of great stories that I don't want to be lost to time. However, in order to properly tell the story of who he is and who our family is, some of what we talk about is gong to be painful, both for him and me, and I want to make sure I approach that in a way that doesn't damage our relationship.

It is certainly never my goal to hurt him or portray him unfairly, but I'm also trying to write an honest account of an interesting and complicated life, including my interesting and complicated childhood, and I'm sure there will be some things in the final edit that are not easy for him to read. I anticipate that there will also be parts of the interview process that are difficult for both of us. Any advice/warnings/helpful stories from people who've done a project like this with a family member, especially if it's a parent?