Step 1: Things you need
Step 2: Measure your pages
Let's say you want a book of the size 15x10cm.
But you have to add 1cm to one side of the book.
Add the 1cm to the side where you want the binding to be. In this case it would be 16x10cm, because it would be a landscape format book. Sort of like the one I made.
Step 3: Make the inside of your book
Measure about 1cm on the left side of each page and mark this line. Then, carefully, score this marked line with the knife. Be careful not to cut the small piece off, you only score it so it's easier to fold the paper.
Once you've scored all the pages, fold them along the marked line.
You will end up with a whole lot of single pages