Wills

A Will is a document that controls the distribution upon death of assets that are owned by you at the time of your death.
In a Will you identify yourself and usually identify your immediate family.
A "personal representative" (also known as an "executor") is named.  This is a person who will administer your property in a probate procedure.  A probate may consist of filing an affidavit with a court (small probate) or the filing of a regular probate.  Primarily, a personal representative distributes property as you have directed in your Will.
If you have minor children, you may designate a guardian for your children if your spouse is not living.
Tangible personal property, such as vehicles, jewelry, clothes, and furniture, are distributable according to a provision in the Will.  
Then remaining property, primarily financial assets, are designated for distribution by the Will.  Real property assets are usually held by a revocable trust and distributed according to the terms of the trust (see "Trusts").