What's a Book of Shadows?

Just an example from Google images, it could be a compound notebook or ringed notebook 

What's a book of shadows, you ask? Ever seen Charmed, well it's almost exactly like that, the potion and spell part. The monster part not so much unless you log the Gods and Goddesses and deities things like that. I myself believe in vampires and the such but that's just me.

Everyone is always worried about how expensive and nice-looking their book is, and that's okay. But your book can just be a notebook or like mine (only temporarily) a virtual Book of Shadows meaning its on the net. Others make scrapbooks and I think mostly because a Book of Shadows is something you pass along your family. For instance you can have a personal Book of Shadows and a family Book of Shadows and a coven Book of Shadows (if you're in one).Or you could just have a personal book you later on decide to pass on to your family. Which I plan to do along with a cookbook (wink!) things I've seen to be consistent is the following

• wiccan rede/creed 
• (they are two different things!)
• spells/rituals
• (categorized by subjects i.e, love, wealth)
• candle colour charts
• herb list 
• (explaining each of the purposes and benefits of said herb)
• tools/altar setup for different occassions
• depending on what you believe in exactly you could have a list of gods 
• (detailing some legends of them, what you do to celebrate them such as holiday)
• rules of your coven or expected of yourself

Now remember all of these are optional you could easily go without one of these. only ones ive seen are required are the wiccan reed and creed those are out anthems of sorts.
Otherwise knock yourself out with what you wanna do with it.
Just make it 'you'.