How do I utilize the root notes of a scale to give my solos a better sound?

Answer 1

There's only one root note in each scale. The root is the first note of the scale, the note after which the scale is named.

For example, the root of the C Major scale is the note "C". This note will sound good when a C Major chord occurs in the music. The root of a D major scale is D, for an E Major scale it's E and so on.

If you build a scale on each of the notes of the C Major scale (C D E F G A B), you get seven different scales, or seven different modes of the C Major scale, each with their own root and related to different chords. The chords are as follows:
C Major
D Minor
E Minor
F Major
G Major
A Minor
B Diminished

If you play the notes of the CHORDS, including the chord's root note you'll get better solos. For example, see the names of the chord tones in the table below) the notes of the C Major chord are C E G. You can add the A note to form a Major 6th or the B note to form a major 7th. When you play C E G and A over a C Major chord it will sound very nice.
C Major - C (root) E (3rd) G (5th)
D Minor - D (root) F (3rd) A (5th)
E Minor - E (root) F(3rd) B (5th)
F Major - F (root) A(3rd) C (5th)

Figure out the notes in each chord of build on the notes of each of the 12 Major scales and you have a way to navigate any song in any key.