Start with high-confidence portraits books, then narrow by subgenre or adjacent topics.
Colored Pencil Painting Portraits
Alyona Nickelsen
Sargent Portrait Drawings
John Singer Sargent
When We See US
Koyo Kouoh
Out of Many, One
George W. Bush
Portraits of Courage
George W. Bush, Laura Bush
The Artist's Complete Guide to Facial Expression
Gary Faigin
Painting Portraits and Figures in Watercolor
Mary Whyte
Portrait Painting Atelier
Suzanne Brooker
Roar!
Ashley Longshore
The Art of the SNL Portrait
Mary Ellen Matthews
Lessons in Masterful Portrait Drawing
Mau-Kun Yim, Iris Yim
How to Draw Lifelike Portraits From Photographs - Revised
Lee Hammond
Drawing Animal Portraits in Coloured Pencil
Lisa Ann Watkins
Rembrandt. the Complete Self-portraits
Marieke de Winkel, Volker Manuth
Gainsborough
Ruth Dangelmaier
