Feel your way around the piano, as matching sounds with hand placement will help you get a sense of the instrument's range and be able to locate notes quickly. The piano is comprised of black and white keys, with the black keys in groups of two and three. Any white key immediately beneath a group of two black keys is C; the C located in the middle of the piano is appropriately called "middle C" and can serve as a home base if you get lost. The note names in between go in order of the alphabet and start over at A after G; black keys make the note sharp (if higher) or flat (if lower).
Learn simple melodies using intervals, or note distance, from common tunes. Familiar songs help you sound out other melodies because you can use those associations to figure out intervals quickly. For example, if you begin at middle C and count that note as one, play the subsequent three notes to get to the fourth note, or F. You have a perfect fourth, which is the interval formed by the first two notes of "Here Comes the Bride." Any time you hear a melody containing that interval, you know to play the next note on the fourth step from the first.
Play chords. Melodies are traditionally played with the right hand, while the left hand plays chords for the supporting harmonies. Simple chords in Western music are based on triads, or groups of three notes. To play a C triad with your left hand, simultaneously place your left pinky on middle C, your middle finger on E and your thumb on G; this is called a C-major chord. Play triads based off of other notes and experiment with nearby black keys to form different types of chords.
Listen to songs you like and sound out small sections of them. Using your understanding of intervals and listening to the music's overall shape, you can reproduce its basic melody. Learn only a few notes at a time so you don't feel overwhelmed or frustrated. Repeat small sections until you can fit them together to make larger phrases, like putting together a puzzle.