The minor scales work similar like major scales, but the use a different pattern of intervals. The following illustration shows the simplest minor scale, the A minor scale:

The A minor scale is not only the simples one, it also visualizes the general pattern of all minor scales on the piano keyboard.
The Major Scale Pattern
The pattern of intervals for all minor scales is:
As with the major scale, you do not need anything fancy to remember this pattern either. If you have a piano keyboard in front of you, just look at the intervals of the white keys, this time starting from A. This is the minor pattern, that you can apply to any key.
All 12 Minor Scales
And like with the major scale, there are 12 possible root notes for the minor scale as well. Each scale starts at a different note, but uses the same pattern.

Each column in the illustration above describes one of the minor scales. On top, you see the key and therefore the root note of the scale. Each dot on the column is one of the notes in this scale.
The notes have almost the same name as the ones in the major scale. The only difference is the 7th note, which is called subtonic instead of leading tone.
- ● Tonic
- ● Supertonic
- ● Mediant
- ● Subdominant
- ● Dominant
- ● Submediant
- ● Subtonic (the only difference to the major scale)
- ● Tonic (the same note, the same as 1)
You don’t need to remember these names. An important fact is, that each of the shown major and minor scales are a set of seven different notes.