If you intend to leave property to your minor child, you may want to consider conveying that property in a testamentary trust. A testamentary trust is created by your will after your death, and can be used to manage property for your children's (or another person's) benefit. For example, say you want to leave $10,000 to your 12-year old child. Instead of making a direct gift in your will, you could place the money "in trust" and assign an adult to handle the money until your child reaches a certain age or finishes school.
The person you name to take care of the property is called the trustee, and your child is the beneficiary. The trustee is usually the person you appoint as the guardian to your children, but it can be someone else you appoint instead.
Many rules apply to the trustee. For example, the trustee must act in the best interest of the beneficiary. The trustee cannot mishandle the property or use the property for his or her own benefit.