You can draw up an "advance health care" directive which will specify who can make medical decisions for you if you are disabled/incapacitated, and also draw up a "springing power of attorney" which will come into effect on your incapacity and give a designated person the right to make economic, legal, etc. decisions for you. This will take care of you, *and* the POA can also let the same "attorney in fact" (the person you give the power to) make economic decisions about your income or assets in regards to your children.In case of your death, you can in your will create a testamentary trust in which you'll put any assets you have for the benefit of your children and direct the trustee (the person you designate) how to spend or distribute them for your children. You can also designate who will get guardianship of your children IF when you pass, there are no living parents.What you can't readily do in advance is to  cut out your children's father's unless they have already voluntarily given up parental rights and/or unless there has been a court adjudication or determination that they have lost their rights, unfortunately. Parental rights cannot be unilaterally cut off by one parent, so while you can exercise considerable control over your money, and indicate who you'd like to get guardianship of your children, if the fathers appear and want to take the children if something happens to you, they will likely be able to, unless some other reletive (such as a grandparent) brings and wins a court case to have the children given to someone else.None of these documents are easy to do--they are very technical. You are advised to retain an attorney to help you.