Start with high-confidence death & grief books, then narrow by subgenre or adjacent topics.
Confessions of a Funeral Director
Caleb Wilde
Briefly Perfectly Human
Alua Arthur
Dying
Pat McNees
I'll Hold You in Heaven
Jack Hayford, Jack W. Hayford
Grieving With Hope
Samuel J.I.V. Hodges, Kathy Leonard
Good Grief
Granger E. Westberg
The Other Side of Sadness
George A. Bonanno
Grief Day by Day
Jan Warner, Amanda Bearse