Disassemble the cereal box by cutting it along all the seams. This will give you two panels large enough to work with.
Cut a 9-1/2 inch by 6 inch square out of one of the cereal box panels to make a cover. You can measure and mark the cardboard lightly with a pencil to guide your cutting.
Fold your cover in half to make the front and the back of your book.
Fold your white paper in half and then in half again so that it is in quarters. Then cut your white paper along one fold.
Place your paper into your folded cardboard. Press down on the crease to hold your book together.
Punch holes in your book, then thread through with ribbon or string to hold the book together. You can now fill your book with whatever you want.