It depends...the perennial answer.
Two years on, I'm sure the original poster either made a map of their property...or didn't.
I really appreciate George's answer.
I think there are a few important principles, a number of which have already been touched on.
First, if we are going to make a map / plan, who is it for? As noted, for taking a PDC, creating layouts is an important part of being able to communicate an idea, particularly with respect to land. A PDC student attempting to earn a PDC certificate needs to be able to communicate their ideas to the instructor / mentor as evidence that they understood the concepts that were taught and can apply constraints to their design. If you need others to help implement your design, whether friends and/or family in a permaculture blitz, or professionals you hire to implement part of your plan, then some representation is crucial. Of course, if you are designing for someone else, the map or layout is likely necessary as part of the deliverable of the design. Would you want someone to just start building without and architect's or engineer's blueprint to guide them?
Another item is how we see things and understand them. Some people can see and understand a layout and others don't really get it. We're all different.
Observe and interact - this is a key principle. If you've been on a property for some time, long enough to have seen what happens in various seasons and conditions like moisture, water flow, sun and shadows and such, and you are doing the project for yourself, then perhaps you don't need one.
As others have noted, it can also be a long term tool to keep track of what is done, what is yet to be done, and what is where. It's also something that may be quite appreciated when the property changes hands at some point in the future.
Now, I hope I don't type this too harshly...a map or layout is not a permaculture design in and of itself. It can be a tool to help visualize what is happening on the property (such as water flow, shade, etc) and it can be a communication device to help someone else understand what the plan is. It can be a visual of part of your design, but permaculture isn't just about designing a garden along certain principles. Store and capture energy is another permaculture principle - it could be difficult to represent things like elevation changes and that impact on design that has (water flows downhill, or being able to plan your rounds / chores by moving on contour than uphill and downhill and back). Of course, the more complex, and the larger the design becomes, the more important this can be. Imagine if Wheaton Labs, in the mountains of western Montana, didn't take elevation into account.
Part of the question was how to make it fun. That also depends on what is fun to you. For some people, sketching with pencil and paper and a geometry set is fun, for others it may be a computerized design tool, for others, cutout representations, for others a diorama (paper mache, clay / play dough, Lego, or other materials) may be fun. It seems to me I've seen, or perhaps heard of, someone creating a layout in Minecraft. For folks in a relationship or family, perhaps working something out together could be fun (and the others may take more ownership if they were involved).
For me, looking at a layout of our plantings and gardens, I work with She Who Must Be Obeyed. If we don't have a plan communicated as to what goes where, we often wind up with one disappointed that something didn't wind up where they think it ought to go (or where it was in their mind's eye). I'm trying to use an online garden planning tool called Seedtime. I've got some of our layout done, but it's more than that as you can also input your crops (and there's a planning calculator that can suggest how much of something you want to plant) and it will suggest when to plant, transplant, or harvest based on your growing zone and average frost dates. If I can get the layout there completed, then it's another planning tool in our toolbelt and can conceivably reduce some family feuding.
