Is your product safe? Is your water safe? The Environmental Working Group is a non-profit organization that provides useful resources to the public about the environment and products/foods/etc that contain toxic contaminants.
Specifically, note this document that lists the foods most toxic due to pesticides and other environmental contaminants, as well as which foods you should buy from organic sources.
The Paleolithic Diet is a program that mimics the diets of paleolithic period, when humans were hunters/gatherers.