A will decides where your assets and property go upon your death. You can name an executor to administer your will who is given powers and compensation for handling your estate. If you have minor children, you can name a guardian for your children and their property. You should review all of your assets and decide who you want to have them. Remember that a will is not for yourself, but for your family who will survive you.
Note that any asset that contains a beneficiary, such as a life insurance policy, an annuity IRAs, jointly owned property or assets, do not pass through a will. Instead they go directly to the named beneficiary.
Even if you are married, it is important to have a will not only for assets in your own name but in case your spouse dies before you. Then all of the marital assets (his and yours) will pass under your will.
It is important to revise your will whenever there are changes in your life or changes to the persons in your will.