Start with high-confidence divorce & separation law books, then narrow by subgenre or adjacent topics.
This Is How Your Marriage Ends
Matthew Fray, Rob Shapiro
Prenups for Lovers
Arlene Dubin
The Ties That Bind (routledge Revivals)
Carol Smart
The Great Divorce
Ilyon Woo, Suzanne Toren
Divorce After 50
Janice Green
A Divorce in Salem
Laurie Pittman, Laurie S. Pittman