The A minor chord (written as "Am") consists of the first, third and fifth notes of the A minor scale: A, C and E.  

A chord is played in its "root position" when the low note is the same as the note in the chord's name (i.e. an A minor will be in root position when the low note is an A).

To play A minor in its root position (as shown in the video), first place your thumb on the A note of your keyboard. A is the white key that's between the second and third black key of the group of three black keys. It is the second white key below C. 

The next note in the A minor chord is C, which is the third of this chord. In the A major scale, the C is sharp (a black key); in the A minor scale the C is natural (a white key). The third is the most important note of a chord: it determines its major or minor character. Position your middle finger to play the C key.http://www.playpiano.com/Tips/MinorChords.htm 

Next, place your pinky on the E key. The E is the 5th of the Am chord and is two white keys above C.

Once you have all three fingers in place, strike the three keys in unison to play the A minor chord.

After you're comfortable playing the root position, you can learn new ways to play the A minor chord by using inversions of that chord. An inversion uses the same exact notes, but substitutes different notes for the lowest pitch. Since the A minor chord has only three notes, it has one root position and two possible inversions.

You can play the different inversions by adding notes with your left hand. If you play an A note an octave lower than your A minor chord, it will still be in root position

To play a first inversion, play a C (the third of the chord) with your left hand. To play a second inversion, play an E (fifth) as the bass note. 

As you start feeling confident playing different inversions of the A minor chord, you can try to play the chord in sequence with other chords. A sequence of chords is called a chord progression. All songs contain chord progressions.

The A minor chord is used in many songs. You will need to use this chord to play songs such as  and I Will Survive by Gloria Gaynor. 

Some songs that have chord progressions that incorporate the A minor chord are Bad Romance by Lady Gaga and Love Story by Taylor Swift. 

In order to play the songs you will need to learn the other chords in the progression. For example, the jazz standard L.O.V.E. calls for A minor chords, but you will also need to learn the C major, D minor, G major, B major, F major and G major chords in order to play L.O.V.E.