Penny Halliwell often noted that she created most of the potion recipes in it (as Evil Witch Vanquishing Potion), though the only other entries we know for a fact that she wrote were the entries on the Necromancer, the Ice Cream Man, Gammill, The Collector, and Eames. After Melinda was burned at the stake, the book first passed to her daughter Prudence before then being inherited by each generation of her descendants. Among the earliest entries added to the book when Melinda was alive is a curse, possibly along with the entry which details the coming of the Charmed Ones in woodcuts (which is mentioned by Phoebe in Something Wicca This Way Comes.?), though this could've been done by a future descendant. Although it was fairly small then, each succeeding generation of Warren witches had added numerous pages to it, including information that they came across and felt necessary to be recorded for future generations of Warren/Halliwell witches. This actually creates a small continuity error within the series, as Melinda is known to have died in 1692 however it is possible that she created the book, and her daughter Prudence started adding to it after her death. The Charmed Ones' book was started by Melinda Warren, the progenitor of the Warren/Halliwell line of witches, and is dated with the year " 1693" written on its cover page.
2 Attempts at stealing the Book of Shadows.