State Court Rules
Our system of federalism prescribes a different set of court rules for every state. Here are two examples:
In addition for being useful in trial scenes, state courts usually have rules for probate and so could be useful in stories about tangled inheritances.
To locate the court rules for the state in your story, try searching your favorite search engine for [name of your state] “rules of court.” Sites with URLs ending in .us or .gov are the likeliest to be the official versions. Or at least as official as online versions are allowed to be. Many courts will only accept resources published in print as official.