Your split-page script should contain:
Action-side descriptions of:
• Each shot (who, what, when, where)
• Its action content
• Camera movements
• Optical effects (fades, dissolves, etc.)
Sound-side descriptions of:
• Dialogue, word for word
• Positioning of dialogue relative to the action
• Music starting and stopping points
• Featured sound effects (that is, other than synchronous, or “sync,” sound)