Looking strictly at health benefits of eating a whole-foods plant-based diet across the life span, these websites may be of interest:

1) Whole Foods, Plant-Based diet,
as described by Center for Nutrition Studies

2) Forks Over Knives.
The website contains both free and paid resources.
Main page - https://www.forksoverknives.com/
Beginner's Guide - https://www.forksoverknives.com/how...ginners-guide-starting-plant-based-diet/
Documentary - https://www.forksoverknives.com/the-film/