Saddle-stitching is a common binding method for small booklets, calendars, pocket-size address books and some magazines. Binding with saddle-stitching creates booklets that can be opened up flat. The binding method is a good binding option for booklets with a relatively low page count.
My final page size was something like 13.75"x11". I left a 1.75" margin on the right side to accommodate the binding, so my printable area was 12"x11". Use an adjustable 3-hole punch to figure out where your screw posts are going to be. This will be trial and error, depending on your hole punch.