Photos and images on this site will be to the best of the editor's abilities cited with: photo credit or image credit.
Public domain is currently at 1927 for the year 2019.
Since a judge ruled that artwork in museums photographed as stills/reproductions and not artistic exhibitions, then photographic images can be argued to be in the same category for some photos, but not all, photos. It depends on the laws at the time of when the photo was take, etc.
If you have permission of the family, and the photo is not of a live person, then photos can be used in most cases. If you know the photographer, then written permission to use family photos for books would be the way to go to avoid any copyright infringement.
For documents... paperwork for the government should be public domain since the public funded the creation and distribution of said paperwork like birth certificates. Just like recipes, forms that are to be filled out cannot be copyrighted.
This actually happened to the editor when she worked at a community college back in the 1990's. The ADA paperwork everyone has to fill out for new job postings had been copied so many times over that it was illegible. So she got out PageMaker and redid the 8-10 pages of the federal document. The result looked nice and professional.
The Human Resources department yelled at her for going against copyright. Upset, the editor went online to the copyright office of the federal government where it clearly stated that forms are unable to be copyrighted as well as most, if not all, government paperwork has been paid for by the taxpayers and therefore are in the public domain.
For family photographs, be sure to obtain written permission from family members like in an email. If the person is too old, then be sure to get that emailed permission from one of their children to clear you from any liability.
If someone in the family does not like the photo or photos being used because you will be making money off the book, the editor is laughing hard now... NO ONE makes money off family genealogy books worth any family blow out. Most family genealogies are only of interest to the families themselves.
That is why the editor gives the electronic versions out for free, print editions are too expensive to be produced and sold for nothing, to family and lets professional genealogists who really need your work pay the $5-10 for your time and effort.
Are we good now?
Good, because the editor still has never received an apology from HR. ;)