This is a list of some terms and their definitions with which you might not be familiar.
Sewing jig (bookbinding) Also known as a piercing jig. A folded piece of paper with the position of sewing stations (holes for sewing signatures together) marked down the fold. This is placed inside each signature to mark sewing stations so that all the sections have the stations at the same places.
Signature (bookbinding) Nested, folded sheets of paper that form a section.
Sketchbook A book or collection of papers and other materials that are used for sketching and developing ideas.
Viewfinder A rectangle with a window cut out of it or two L-shaped pieces of card overlapped to make a rectangle with a window in it. Look through it to help you choose parts of an picture or thing. You can look for the most interesting part, or the most colourful, or the most calm, or whatever you want.