From publisher blurb:
Each book in the Echelon Reference Series is written to be a complete reference for a single topic.
This book focuses on the barbarian class, savage warriors whose fury is legendary.
Barbarians are meant to be overwhelming, but this book can help.
In this book you will find 1 class, 26 archetypes, 104 class features, 257 class subfeatures (including 228 rage powers), and 236 feats, all accessible or directly related to the barbarian class. Also, 59 stat blocks for a mix of NPCs of levels 1-20, and monsters with levels in the barbarian class.
This book contains material from the PRD and from third-party publishers.