Hi Nannyof3,
 
I would definitely recommend having a nanny contract to establish boundaries, expectations and responsibilities for both the nanny and the parent. Caring for children is serious business and whether I were a parent or a nanny, I would definitely want to be explicit about the job. I assume nanny agencies take care of this, but for independent nannies not associated with an agency, I would recommend reading the following articles and using them as a guide if you choose to create your own contract.
 
http://www.education.com/reference/article/Ref_Nannies/
 
http://www.4nannytaxes.com/NEWS/nanny-contract-agreement.cfm
 
http://www.absolutelynannies.com/NannyContract.html
 
http://www.ehow.com/how_13089_write-contract-nanny.html
http://www.ehow.com/how_5088527_create-nanny-contract.html
 
In addition, I sent a note out to a friend who's currently on vacation, but has had a lot of recent experience with nannies. If I hear back from her, I will share her experience with you.
 
Thanks for submitting your question and best of luck!
Lori

Here's another link I found about nanny and parent expectations and recommendations, when traveling that you might find helpful. It's from the New York Times.
 
http://travel2.nytimes.com/2005/09/18/business/yourmoney/18nanny.html?_r=1&pagewanted=1