Daily sign-in / sign-out sheet.

"Who is in this building right now?" is the question behind fire drills, ratios, licensing visits, and every parent's peace of mind — and the sign-in sheet is the only document that answers it minute by minute. It's also a legal record: exact times and real signatures are what make it hold up, which is why the sheet insists on both.

• The adult signs, every time. Staff can note times in a pinch, but the signature of the person who dropped off or picked up is the point of the exercise — it's your proof of custody transfer at both ends of the day.
• Exact times, not "about 8." Ratios are calculated in minutes, subsidy billing is paid in hours, and "when did he arrive?" after an incident deserves a real answer.
• Take it to the meeting spot. In a drill or evacuation, the day's sheet is your headcount roster — which is a good argument for a clipboard by the door rather than a binder in the office.
• File by month and keep them. Retention periods vary by state (several years is common); the boring box of old sign-in sheets is also your evidence for subsidy audits and licensing reviews. And remember attendance records must survive even after a child leaves your program.