The first seven letters in the Roman alphabet--A, B, C, D, E, F, G-- constitute every note that can be played on a piano. This "musical alphabet" begins at A and ends at G, then repeats an infinite number of times. For example: ....F,G,A,B,C,D,E,F,G,A,B, etc.
Between these notes are flats and sharps. A flat is represented by a 'b' next to the note, while a sharp is represented by a '#.'
When confronted with a flat, play the note one key lower than the key you would regularly play. For example, if you need to play a Bb, play the black key one step behind the white-keyed B on the keyboard.
To play a sharp, you must play the note one key higher than the key you would regularly play.
A flat can also be a sharp. Whether a note is a flat or a sharp depends on the scale. Since the notes must be written A,B,C,D,E,F,G, and you cannot skip or repeat a letter, some scales will write one note as a flat, and another as a sharp.
For example, look at the D scale: D, E, F#, G, A, B, C#
This is because a scale can neither skip a letter nor repeat a letter; it must go from the root note (in this case D) to the last note (C) without skipping a letter or repeating one. This rule applies to every scale imaginable.
The piano has only two clefs, the treble and the bass. These signs tell you whether to play a high note or a low note. The treble clef is for high notes, and is usually played with your right hand. The bass clef is for low notes, and is usually played with your left hand.
Musical notes are written on lines and spaces, otherwise known as the staff. When reading notes on a staff, you go from the bottom of the staff to the top. The notes on the staff alternate from being written on a line, to a space, to a line, and so on. For example: A = line; B = space; C = line; D = space. These notes will also be located right next to each other on the piano's keyboard.
The letters written in the spaces in between the lines on a treble clef are FACE. F is the lowest note, and E is the highest.
The letters written on the lines of the treble clef are EGBDF. E is the lowest note, and F is the highest. A useful acronym to help you remember this is "Every Good Boy Does Fine."
The letters written in the spaces in between the lines on a bass clef are ACEB.
The letters written on the lines of the bass clef are GBDFA. A useful acronym to help you remember this is "Great Big Ducks Fly Away."
In songbooks for the piano, the staff with the bass clef is located underneath the staff with the treble clef. This makes sense, since the treble notes are higher musically than the bass clefs.