War and the Noble Savage

i would start with the slide cast linked to below, as it is a good overview of the book and its key points -- a look at both the history of the notion of the "noble savage" as well as analysis of recent theories concerning them and pre-civilization.

War & the Noble Savage
A Critical Inquiry into Recent Accounts of Violence amongst Uncivilized Peoples

people who have taken an interest in the recent "declining levels of violence through history charts" may find this especially interesting.