Twelve years old should be the absolute minimum. Younger children do not have the emotional or physical maturity to deal with many of the problems that could arise. A good rule of thumb is the younger the children being watched, the older the babysitter should be.

References

Sitters should provide references that indicate a proven track record for showing good common sense, maturity and following instructions.

First Aid

Sitters should have first aid training and know the Heimlich maneuver to help choking victims. Knowledge of CPR techniques for infants and children is also important. Make sure the sitter knows where your first aid kit is located.

No Surprises

There should be no surprises on either side. Before a sitter is left alone with the children, fees, house rules, discipline, etc. should be clearly discussed.

Emergencies

Sitters should always err on the side of caution. If a babysitter suspects that a child in their care needs professional medical help, they should get it, even if it later turns out to be unnecessary.

House Rules

Make sure everyone understands the "house rules" in terms of what is permissible, for both the sitter and the children. Examples include whether or not guests are allowed, guidelines for telephone use, permissible snacks, etc.

Checklist

Keep a list of qualified babysitters. In case your regular sitter is busy, you won't have to take "just anyone" at the last minute.

Tell the sitter where you will be and how to reach you by telephone. Leave the number by the telephone.

Make sure the sitter knows how to access emergency medical services such as the ambulance or the local hospital. If you have the 911 emergency number in your area, explain how it works and how to use it. Also, put the number of the poison control center by the telephone.

Give the sitter the shortest route to the nearest hospital emergency department in case he or she must drive there. If the sitter does not drive, make arrangements with a neighbor who could be contacted in case of an emergency. Explain that they should use the hospital's "Emergency Department" entrance and make sure they know where it is.

Leave the sitter a list of current health problems any of the children have and what medications or other treatments are prescribed.

If the sitter has to give medication, either measure it in advance or have him / her practice measuring it until you're confident it can be done properly.

Give the name and number of a nearby friend or neighbor who can be called on quickly for assistance.

Explain the significance of the "consent-to-treat" form (PDF document - 37k), sign it in the sitter's presence and instruct him / her to take it to the emergency department if the need arises. This form may not be legally binding in every state. (Check with your local emergency department.)