Create Booklet makes it so easy for technical manuals.

The developper put much effort into this and it shines! The overall feel & use is premium – a gem for a few dollars.
The direct application integration to my Pages / Preview print service is the simplest. Great customer support to work out some bugs on my older Mac. Tried another of his apps (Good Times) and just as equally well thought out.
Update: With every new iteration comes better features. Now can directly open via my documents folder. Also added a landscape mode for a top hinged booklet (as a check book or automotive tally).

Lulu Dooblydoo about Create Booklet, v1.2.2