One of the biggest advantages in hiring a professional babysitter is the fact that she would be trained for administering first aid every time your child may get injured while playing or may have a fall down the stairs.
In event of such happenings, your sitter should know how to deal with the situation. Of course, her treatment may not be considered as the ultimate solution, but it would definitely help until further medical help arrives. You may wish to brief her about the illness or allergies your child may be suffering from and the course to take in case of such emergencies.
Parents of infants need to be especially careful. Your baby has specific needs and these may vary from those required by the other. So, inform your sitter about any such special needs your baby may have.
For example, your baby may not take too well to a particular brand of baby food. Give her the mandatory instructions on how to handle a baby; for instance, to hold a baby neck if the baby is less than four months of age.
You need to be especially careful if the babysitter is a teenager who baby-sits for pocket money. Chances are that she may not be adequately trained to handle your child.
Leave the list of all-important numbers with the sitter. These should include the number of your pediatrician, the contact number of a poison control center, the number of your closest relative and of course, your number!