A Book of Shadows is a witch's right hand tool. (My page on this can be found at this link Book of shadows) It is where they write down everything they have learned. You can't hope to remember EVERYTHING! No matter how you create you BoS, hand written or typed, you should be the one to create every word and page within it. If you photocopy the pages from another person you are creating just another copy of someone else's book. There will be parts you miss and possible mistakes you won't catch. You should create your own Book of Shadows as a reflection of you. Keep it safe and take care of it and in times of need it will take care of you! Buying a blank BoS is fine, but buying a prewriten book is just not acceptable. Besides any good witch takes pride in the creation of their BoS!
Blessed be,
Lady Alice