7. If you plan on running your boards through a planer after joining them
the witdth of your jointer should equal the size of the boards you plan on
planing. There are tricks, however, that some woodworkers use to get
around
this, i.e., jigging up a planer to join a board; jigging up a router to do
the same thing.

Could you please clarify what you mean? Are you saying that if I want to
plane a board 12" wide that I jointed from narrower boards, I need a 12"
wide jointer?

- Owen -