Start with high-confidence wills books, then narrow by subgenre or adjacent topics.
Beyond the Grave, Revised and Updated Edition
Jeffery L. Condon
The Wall Street Journal Complete Estate-planning Guidebook
Rachel Emma Silverman
Ethical Wills
Barry K. Baines
The Executor's Handbook
Theodore E. Hughes, David Klein
ABA/AARP Checklist for My Family
Sally Balch Hurme