Writings by J.R.R. Tolkien, compiled and analysed by C. Tolkien
This book actually took me nigh on 6 months to read. It is full of the history of the rings, and clearly shows Tolkien's story and history development process. Towards the end, a couple of incomplete manuscripts are included and C. Tolkien proposes an outline from various scraps of details found in those manuscripts. This is not an easy read, but if you want to know much more about the history of the Lord of the Rings, and how Tolkien actually developed his world and stories, this is an excellent book.