Listen to the piece of music you want to notate and make a list of all the instruments you hear (e.g., drums, guitar, flute, piano, violin), including the vocalists.
On your staff paper, assign one staff for every instrument on the list of instruments you made (two staves for keyboard parts). Place full scores in the following order, putting the higher-pitched instruments higher on the staff paper for each section: woodwinds, brass, strings, percussion. Vocals should be placed above piano staves.
Write the clef for each instrument on the staff assigned to the instrument. Most instruments will use the treble (G) or bass (F) clefs.
Listen to the first few bars of the music and use a piano or other instrument to determine what notes are in the first few chords. If one note sounds as if everything else is centered on it, this is probably your "home" note, the note upon which the key of the music is based. Write in the key signature for the music to the right of the clef on each staff.
Listen to the music again for where the emphasis and grouping of the rhythm is. This will tell you how many beats are in each measure--the strongest beat usually is beat 1 of the measure, so you can count how many beats are between these stronger beats to get a feel for the measure organization.
Listen to the first few bars of the music. Listen just for what instruments play at particular points and draw a light line on the staff for the playing instrument to indicate a general idea of the pitch direction. Go through the entire piece this way.
Listen to the music again a few measures at a time, this time writing in the basic rhythm for each instrument.
Listen to the music one more time and identify the exact pitches each instrument is playing. Use your instrument to help you. Write in the pitches, combining them with the rhythm notation you already have outlined.
Listen to the music one final time to take note of where dynamics and style markings should be placed; write them in the staves for the appropriate instruments.
Write in the title, tempo marking and composer at the top of the staff paper.