This is Magi-Nation. The book is the Book of Elders.
Per Wikipedia:
Three thousand years ago in the Moonlands, the evil Shadow Magi Agram was sealed inside the planet's Core by the Core Glyph and the Dreamstones which provided its power. Now he plans to escape by using his Shadow Geysers to weaken his prison in order to bring the Moonlands under his control, and only a Magi known as the "Final Dreamer" can stop him. A young boy from Earth, Tony Jones, is summoned into the Moonlands as he is believed to be this Final Dreamer. He joins forces with the apprentice Magi, Edyn, and the Shadow Stalker, Strag, on a mission to gather the Dreamstones before Agram is set free. Using the Book of Elders, the three travel through the Moonlands while combatting the forces of Agram and gaining an ever-growing collection of Dream Creatures from the Moonlands that they visit.
The description of the book from the Magi-Nation wiki says:
The Book of Elders is a book that was made by the elders of the Moonlands in order to trap Agram within the Core. The book gave clues to guide Tony, Edyn, and Strag to find the Dreamstones. Once all of the Dreamstones are inserted into the book's cover, the Core Glyph is formed and can imprison Shadow Magi in the Core.