When I teach guitar I teach the usual aspects, such as how to tune and string a guitar, read music and tablature, the notes, scales, chords, modes, theory and technique. But, I also teach the music business as well and there is a lot to learn in this area. Things like:

What Equipment does a band need.
How to get an agent.
Recording a CD.
What goes into a promotional package.
What do all the FX units do.
How many songs does a band need to know.
How much money should a band charge to perform.
Contracts.
and many other aspects of professional musicianship.

I also think it is most important to keep the student interested and inspired to play frequently.
As soon as possible I record the student on their instrument playing a part of a complete song. This is put on CD for the student to keep. As the student progresses more parts are added to the recording. This creates good incentive for the student to want to learn more. This is generally done before scales are even introduced.