The scales shown here are in the same format as a chord diagram. They are all moveable forms. The "root" or letter name of the scale is located on the circled note. To play a particular scale, move the scale form up and down the fingerboard until the circled note is on the letter name you want to play. For example, if you move the "E Form" scale up the neck so that the circled note is on the 3rd fret, you will be playing the "G scale." If you are not sure about the location of the notes on the fingerboard, use the fingerboard chart I have included at this site.
These scale forms are named after the moveable chord forms from which they are derived. The following chart shows the corresponding chord forms.

 
If the "C form" chord or scale is played with the circled note on the 4th fret, it will be a C# or Db. With the circled note on the 5th fret, it will be a D, 6th fret D# or Eb, 7th fret E, 8th fret F, 9th fret F# of Gb, 10th fret G, 11th fret G# or Ab, 12th fret A, 13th fret A# or Bb, 14th fret B, 15th fret C.
When working with the "A Form" chords and scales, with the circled note on the 2nd fret, it will be a B. On the 3rd fret, it is a C. From the 4th fret on, the location of the circled notes are the same as those of the "C Form"
When working with the "G Form" chords and scales, with the circled note on the 4th fret, it is a G# or Ab. On the 5th, fret it is an A, 6th fret A# or Bb, 7th fret B, 8th fret C, 9th fret C# or Db, 10th fret D, 11th fret D# or Eb, 12th fret E, 13th fret F, 14th fret F# or Gb, 15th fret G.
When working with the "E Form" chords and scales, with the circled note on the 2nd fret, it will be a F# or Gb. On the 3rd fret, it is a G. On the 4th fret it is a G# or Ab, from the 4th fret, the location of the circled notes are the same as those of the "G Form"
When working with the "D Form" chords and scales, with the circled note on the 2nd fret, it is an E, 3rd fret is an F, 4th fret F# or Gb, 5th fret G, 6th fret G# or Ab, 7th fret A, 8th fret A# or Bb, 9th fret B, 10th fret C, 11th fret C# or Db, and 12th fret D.