Here are some of my favorite references:

Sponsors of Lean After Forty:

Performax Fitness Center - Pete Capra
Scaramouche Fine Photography - Eliot Sher
Advanced Health & Injury - Dr. Charles Marino
White Oak Apiary (Local Bee Pollen) - Michael Bruen
Gold's Gym - Carmel, NY

Diet:

Clinical Nutrition for Pain, Inflammmation, and Tissue Healing - Dr. David Seaman
The Mediterranean Diet - Marissa Cloutier
Fit For Life - Harvey Diamond
Warrior Diet - Ori Hofmekler
Rosedale Diet - Ron Rosedale, MD
The New Glucose Revolution - Jennie Brand-Miller and others
The Omega Diet - Artemis P. Simopoulos
The Anti Estrogenic Diet - Ori Hofmekler
The Expanding Obesity Epidemic - Meridel I. Gatterman, MA, DC, MEd

Exercise:

AthleanX - Jeff Cavaliere
Pace - Dr. Al Sears
The New High Intensity Training: The Best Muscle-Building System You've Never Tried - Ellington Darden Ph.D.
Jumping Into Plyometrics - Donald Chu
You Are Your Own Gym: The Bible of Bodyweight Exercises - Mark Lauren
The Men's Health Big Book of Exercises - Adam Campbell

Self Development:

Anything by Alan Watts
Tribes - Seth Godin
War of Art - Steven Pressfield
No Ordinary Moments - Dan Millman