Understanding scales may at first seem daunting mostly because of the overwhelming number of possible scales. The trick is to start with one or two and when you feel confident move add a new scale to your repertoire. Also keep in mind that certain scales are used the majority of the time. Some blues players for instance use nothing but the blues scale.
The Chromatic scale
A scale by definition is just a series of notes determined by specific intervals. Intervals in music refer to the distance in pitch based on what is known as the Chromatic scale. A fancy word for all 12 notes used in western music. The 12 notes are below but note that an A# and Bb for example are the same note. The name just depends on the key or circumstance. Something you may want to discuss with your teacher in more depth later.
1. A 2. A#/Bb 3. B 4. C 5. C#/Db 6. D 7. D#/Eb 8. E 9. F 10. F#/Gb 11. G 12. G#/Ab
The C major scale
To get you started lets look at a C major scale. A major scale has 7 notes. In the case of C the notes are; C D E F G A & B. To play the C major scale take a look at the diagrams below. In the first example the scale is played using a combination of fretted notes and open notes. In the second example the scale ascends and descends through 2 octaves and is played in what we call 2nd position. The small numbers next to the notation signify the fingering.
C major scale in 1st (open) position
C major scale in 2nd position