Watch the Using Harmonics online guitar lesson by TrueFire from Lead Guitar Greatest Hits Vol. 2
Lesson Source: Jim Campilongo's Sonic Tele
Harmonic overtones are located all over the neck of the guitar but to get effective harmonics, be sure to pick the string with a decent amount of force and to spend some time dialing in your tone. The harmonics usually ring out more clearly if the treble on the guitar is turned up.