LilyPond allows you to indicate fingering by attaching the digit number to a note as an articulation mark: a16-5 will show a "5" as a fingering mark. As with all other articulation marks indicated in this way, you can use ^ or _ to instruct LilyPond to put the mark above or below the note, respectively. It is usually better to let LilyPond decide for itself by using a -.

When entering chords, it is recommended that you enter the fingering with the note to which it is attached, like <as-1 ces-4>4-_. It is possible to enter this as <as ces>4-1-4->, but this not only looks confusing, it may confuse LilyPond as to which digit is intended for which note.

Because the extra digits look like they indicate note-lengths, it is recommended to mark them consistently. For this same reason, it is also recommended that fingering marks be added to source files only after the pitch and rhythm have been double-checked. The source file included with this tutorial puts fingering marks after any other articulation and length marking.