Scale Theory

The chromatic scale
The major scale
Modes part 1
Modes part 2
Modes part 3

Intervals, Formulas & Key Charts

Major scale
Minor scale
Major pentatonic scale
Minor pentatonic scale
Blues scale
Ionian mode (Major Scale)
Dorian mode
Phrygian mode
Lydian mode
Mixolydian mode
Aeolian mode (Minor Scale)
Locrian mode
Spanish Phrygian

Useful References

Scale Formulas
Scale Interval Patterns
Key Signatures