The Book of Shadows is probaly one of the most important parts of this faith. The book is compiled by each individual witch, and may consist of detailed information on rituals, instructions for circle casting and banishing, magical rites, prayers.. anything that is of importance to you. These books are seldom published, or even shown to anyone outside the coven. Such books are extremily important, for without them, the tradition's specific rites and other lore must be carefully memorized and passed down by word of mouth. This may lead to misinformation, and perhaps even forgotten rituals.
The appearance of your Book of Shadows is unimportant. It could be a three ring binder, or a home made book.. it could be anything. The important part is that you treasure it and protect it as you would preserve and protect yourself.