Saddle-stitching or saddle stapling or “booklet making” is common for small booklets, calendars, pocket-size address books, and some magazines. Several sheets of paper are folded (the fold becomes the spine of the booklet) and two or more staples are placed in the fold. For do-it-yourself saddle-stitching you can purchase long, adjustable staplers to reach the fold.
When the document is too large for saddle-stitching it may be side-stitched or side stapled. The staples are placed about 1/4″ or so from the edge. A cover may be glued on. Side-stitched books can’t be opened flat and extra allowance is needed in the inner margin.