All you need to do is grab some press to close bags (I used sandwich size). Staple them together at their bottom, and cover the stapled edge with tape.
My version is a book of colors. There are enough pages for each color. I wrote the color word on a bag sized piece of paper and slid it in a "page". Then, I sent Josh on a scavenger hunt to find one small red item. He then slid a pretend tomato into the correct page. We went on until the pages were all filled. Then he read through the book himself identifying the correct color.
This book idea could easily be adapted for several different types of books. For example, how fun would this be to use on a nature hike to fill with different types (shapes) of leaves. And if it ever gets warm enough to grow any (boohoo) that is just what we will do!