Every situation is different regarding what happens when a person dies. This is governed by Trusts & Estates Law and will typically vary between states. For example, the number of witnesses that must be present and signing a valid will, etc. If you're asking about what you should do in order to prepare for that moment that we all must ultimately face, unfortunately, then that is usually called "Estate Planning." There are attorneys who specialize in this type of law as well as certified financial planners. Getting good, accurate tax advice is also extremely important.
