Learning to play chords on the piano is a close cousin to learning the scales. In order to understand how to build proper chords one must have a working knowledge of the building blocks that make up a chord and that would be the scales.
To best illustrate where to begin understanding the scales we will begin with middle C. The best way to understand where to find middle C is to locate the center two black keys and C would be the first white key just to the left of the first black key.
The C scale would be made up of the following succession of keys:
These 7 keys will all be on the white keys which lead right up to the next C key which means that we have completed an octave, or eight keys.
There is enough knowledge at this point with understanding the structure of a C scale to continue. The first basic chord at this point will be the C chord. Let's begin with the right hand by putting the right thumb on middle C. The index finger will then depress the D key and the middle finger will push down on the E key. The next part is a bit tricky where we will now bring the right thumb under the middle finger and place it on the F key now we can finish our run with the index finger on the G and then the middle finger on the A closing in on our C scale we will put our fourth finger on the B key and to complete our first octave the basic C scale.
Finally, we can begin to construct our first piano chord and since we just learned the C scale, let's go ahead and construct a three key scale which is called a triad. Put the right thumb on middle C and now the next key to be pressed will be the E key using the middle finger and finally to form our first basic piano chord we will use the fifth finger (pinky) on the G key.
We did it, we have formed our first basic C chord. From this point the can be played in succession such as hitting the C key followed by the E key and finally the G key; this is called a broken chord. If we placed our fingers on all three keys at once and pushed them down at the same time would be a solid chord.