If there is one book that has been referred to most on the various online Waldorf resources I try to keep up with it is Rhythms of Learning by Roberto Trostli.
Trostli wrote the Waldorf science bible called Physics is Fun — a book that I am very familiar with — so though I haven’t read Rhythms of Learning myself, based on the recommendations of others and my familiarity with Trostli’s other work, I have no qualms recommending it.
From the book description:
In each chapter, Trostli explains Steiner’s concepts and describes how they work in the contemporary Waldorf classroom. We learn how the teacher-child relationship and the Waldorf school curriculum changes as the students progress from kindergarten through high-school. This book will serve as an excellent resource for parents who want to understand how their child is learning. Parents will be better prepared to discuss their child’s education with teachers, and teachers will find it a valuable reference source and communication tool.
Definitely a must-have resource.