1. Start with a square of double side paper. I think I trimmed mine down to 10" x 10".
The red pen lines are just there so you can see where to fold. Do not draw them on yours.
2. Decide which pattern you want on the outside and fold in half. A Hougie board is handy for this if you have one, but as it's only paper you're folding it's not necessary. Turn the paper 90° and fold again.
3. Fold in the corners.
4. Fold the pointy bit up. "Pointy bit" being a technical term. :-)
5. Repeat this for however many pages you want. Punch some holes along the folded edge and you can now assemble it into a book using book rings, ribbon, or a binding machine and fill it with your tags.
I hope that makes sense. If it doesn't just let me know.