I am planning on making a will. Aside from guardianship and distribution of property, can I state in this will that I do not want lifesaving measures -- or do I need to make a living will too?
What you need is an additional document called a health care directive. Wills are most often not located until after a death -- sometimes weeks after a death -- and by then, your wishes for your final care will be, in a word, superfluous.
You can record your specific wishes for medical care in the directive. (These directives are formerly known as living wills in many states, which is the likely origin of much confusion with standard wills.)
However, that may not be the end of your paperwork. If you would like to name a person to supervise the final care you want or do not want to receive -- usually a very good idea -- you will need to make out a durable power of attorney for healthcare. In a handful of states, you can combine your wishes for care and name the person in a single document, called an advance health care directive. Unfortunately, this efficiency has not caught on widely across the nation. For more information on these health care documents, see Advance Directives, Living Wills, Powers of Attorney: What's the Difference?