What are the days and hours of the position? Clarify the days and hours the parent expects you to work and make sure that it fits into your life.
When does the job start? Make sure you have time to give notice at other jobs if needed, and that you will be available for the first day of work and can be on-time and at your best.
Will you be expected to work on stat holidays and/or weekends? Clarify this so you know in advance, and find out how you can request time off if needed, and if any time off will be given (such as when the family goes away or the parents have holidays).
Do you truly feel that you can handle the age(s) and/or number of children? If you haven't done this type of job before, make sure that you have the skills and abilities needed.
Do you feel that you and the parents can work together as a team? This is vital to a successful relationship with the family. Make sure you can bond together and work as a team raising their children, so you're not against one another, making you feel isolated.
Is the wage fair for this type of job in your area? Nannies should be making at least minimum wage before taxes and deductions, should be compensated for any skills and experience they have, and be paid fair market wage in your area. Talk to other nannies in the neighbourhood to get a sense of what the going rate is.
If it isn't a live-in job, how long will it take you to get to work each day? Make sure it will be worth it for you, and won't become an issue in the future.
What other duties are required, other than child care? Make sure you clarify this before accepting the job and express any concerns you may have. Can you handle giving adequate attention to the children and completing the tasks required?
Do you have any vacations/time off coming up? If you have anything planned, mention this to the parents so they know and can be prepared for any time you need off.
If you are using your own vehicle, is the family going to compensate you for this? If they are, how will they be compensating you? Make sure you know this in advance and know how to track your expenses.