A comprehensive knowledge of major scale fingerings is incredibly important, yet you’d be surprised at how many guitar players I’ve come across that really don’t have a clue to this information.
The following diagrams show a G major scale broken into 8 forms in various positions on the fretboard. You will want to memorize these patterns. You also need to locate the tonic notes in each form (tonic: the note for which the scale is named, in this case G).
The black dots in the diagrams indicate where your fingers go; the numbers in the black dots indicate which fingers you use.
G Major Scale