If you plan on printing and making round badges from the Happy Saints eBooks, a hole puncher will be very helpful indeed. The badges in the ebooks are 2.5 inch in diameter if you print them at 100% size.
Here are some 2.5 inch circle punches you can buy from Amazon. Product links are below the image. You can also consider fancier types, such as those with scalloped edges.
Disclosure: I do not have affiliate links for the links below. I personally own the Uchida punch and find it very good.
Product links: