To be precise you'll need to look at a diagram specific to the 4.6L V8 engine in your car. A repair manual (like a Chilton's or Haynes) for your specific year and model will have a clear diagram showing their exact location and routing. You can also often find diagrams online, by searching for "1998 Lincoln Town Car 4.6L spark plug wire diagram".
Important Note: Be very careful when working around spark plug wires. They can be brittle with age and easily break. Also, disconnect the negative battery cable before working on them to avoid electrical shocks.