Don't know if the authors are really natural, but a great book for natural guys: https://www.amazon.com/Body-Sculpting-Bible-Men-Fourth/dp/1578266114
Covers workouts, diet, nutrition, exercises, etc.
Diets don't work. Get a book on body building and nutrition . https://www.amazon.com/dp/1578266114/ref=cm_sw_r_cp_apa_fabc_-rKcGbGJTQXBA
It'll explain what to eat and why.