Familiarize yourself with the staff if you are not already able to read music. The bottom line represents the note E, and the notes go in order as you move upward, one note for each line and space. The notes run from A through G, then begin again with A. Thus, beginning with the E on the bottom line, the space above that is F, the line above the G, the space above the A, the next line up is B, and so on until you reach the top line, an F.
Write the notes of your song into the staff. Most songs have four beats per measure, so use a quarter note (a filled circle with a stem) for a note that takes one beat. A half note takes two beats, and is a plain circle with a stem, and a whole note takes four full beats, and is represented by a plain circle with no stem. An eighth note, which represents half a beat, is drawn as a quarter note with a little tail attached to the stem.
Write the words to the song under the staff, with each word corresponding to the note of the melody above it.
Finish by placing the accompanying chords above the staff, such as G or F. Follow the melody, and this will show when the musician is to change chords. Once you have written a chord, you don't write any other chord indications until there is a change in the chord.