Learning to Play Guitar

There are a 100 schools of thought about how to teach and to learn playing the guitar. I have tried and read many of them. I think, as most people would suspect, like most learning, that the approach and the result depends on the student. This often translates to the age, interests, focus and passion of the student. Very young children are not good students for the guitar due to its physical nature. Its hard to hold, tune, finger and pick. The piano is always the best instrument for younger students. Its easy to play and its logical. It matches the form of the art. Even if they don't want to, I'd always start young kids on the piano, because that is the best place to learn the basics of music theory. Transferring it to the guitar is not easy, but at least they may learn something of value when they get old enough to manipulate the guitar as an instrument. I would think that few kids younger than 12 can play the guitar well without much pain and consternation. But Mozart played the piano at 3 (or so they said).

These are my personal thoughts, but they are totally biased by my own experiences. These are the obvious areas for exploration, though most should be taught at the same time, in snippets.
1. Play songs using chords, preferably something they know or like
2. Learn the major scale in at least one key in one position across all strings. All lessons should focus on identifying and recognizing the root and should use all 4 fingers.
3. Combine a simple song in the same key with some simple improvisation on that key. Demonstrate the use of the pentatonic scale and the emphasis on the root.
4. Explore how chords fit into a major scale.
5. Explore some of the basics of music theory, as it pertains to the scales, whole and half-tones
6. Expand the same scale down the neck to show how you can play in the same key at different positions
7. Learn some basic barre chords and how they are connected to the scales in position
8. Show the basic blues progression
9. Show the basic blues scale in whatever key you choose (G is good, or E, or possibly C) and improvise there. I like to connect the licks to the chord and position, though ultimately its best to know the entire scale across the entire fretboard.
10. Explore tabs
11. Explore a scale down the entire fretboard and show how different positions connect to different chords and how you can connect logical positions (those with a full barre) to other positions. Memorize the entire fretboard in a major scale.
12. Change keys and repeat.
13. From here you can go anywhere, depending on the student's interest.