Start with high-confidence pencil drawing books, then narrow by subgenre or adjacent topics.
The Hobbit Sketchbook
Alan Lee
Colored Pencil Painting Portraits
Alyona Nickelsen
Pop Manga Drawing
Camilla d'Errico
Sargent Portrait Drawings
John Singer Sargent
The Colored Pencil Manual
Veronica Winters
You Can Draw in 30 Days
Mark Kistler
Drawing for the Absolute Beginner
Mark Willenbrink, Mary Willenbrink
How to Draw Lifelike Portraits From Photographs - Revised
Lee Hammond
Drawing Animal Portraits in Coloured Pencil
Lisa Ann Watkins
The Joy of Botanical Drawing
Wendy Hollender