You need to address hours, pay, vacation, holidays, sick time, inclement weather, and expected duties. You should also consider setting an expectation for notice if either party chooses to exit the relationship. There are samples if you google it, but I've found many of them fail to address some pretty important things, like inclement weather which is a big issue for lots of people each winter.

Are there sample nanny contracts out there? Any important clauses folks recommend?