I have taught acoustic and electric guitar, both one to one and in a classroom setting. Teaching from absolute beginner level to intermediate:
-Basic chords and their uses in popular songs, as well as more sophisticated chords
-Scales and exotic scales, putting them in context with popular songs.
-Rhythms and strumming patterns
-Guitar maintainance including changing strings, making strings last longer, tuning your guitar and keeping it in tune
-Alternate tunings and slide guitar
-Improvisation and making music with others