The most basic chords for piano are called major chords, and have three notes, played with the pinkie finger, middle finger and thumb of either hand. The bottom note of the chord is called the root, the middle note is the third and the top note is the fifth.
The bottom root note defines the name of the chord. For example, a C major chord, has the note C on the bottom, meaning toward the left of the keyboard. To create a C major chord, locate the brand name of the piano inscribed above the keyboard near the center of the piano. Immediately below the brand name, locate a group of two black keys next to each other. The note C is the white key immediately to the left of those two keys.
To play the chord, place the pinkie finger of the left hand on the C note. Then, skip the next three notes to the right (two black keys and one white), and play the fourth note with the middle finger. To locate the top note in the chord, skip another two keys (one white, one black) and play the third key with the thumb. The notes are called C, E and G, or the root, third and fifth.
This is the pattern to play all 12 major chords. Root, skip three, then skip two. The next most basic chords are called minor chords and are created by skipping only two notes from the root, not three.