Want to make your own notepads? Your key requirementsis a special type of glue known as padding compound.
Crafting weblog Chica and Jo shares explains how padding compound lets you turn nearly any stack of paper into a pad by securing the sides with binder clips and brush the compound around the edge of the pad. You can add a cardboard backing if you want a sturdy backing. The author recommends using a piece of regular white paper on the front and back to protect the notepad from glue drips.
Padding compound is used in bookbinding and normally sells in larger sizes, but you can find smaller quantities with a little hunting (try specialist craft sites and eBay).
Make your own custom notepads [Chica and Jo]