It should be obvious, really, but if you look at a decent LEGO design, you will hopefully see that it essentially distills the object to close to a minimum set of elements and features that make it what it is. It is really an outline of a real world object, it's 3D blueprint, if you want. Of course, due to the restrictions of the basic design of the LEGO interlocking system, there are lower limits to the size of a model, which forces very small models (like the one depicted here) to use elements that are less universal (e.g. the wind-shield part of the motorcycle here). However, if you were to build a scaled up model of the same motorcycle (policeman included) you would have found that you can use just a handful of very basic blocks (plain and angled brick alone would do for a large enough model).
But this is almost by-the-by. The important thing, and the eternal quality of LEGO, is in its manifold benefits to all who give them more than just a cursory glance. At first glance, it may seem that a lot of the sets now available do not in fact encourage either creativity or this "model as a blueprint" effect. But I think this is not the case. Yes, at first stab, and for a few of the first sets you get your hands on, you will most likely just follow the included (pictorial!) instructions just to see the final model as it is shown on the box. But if you (or your parents) stick with LEGO by buying just a few more sets, or even better, a generic brick box, sooner rather than later you'll be tempted to take your models apart and put them together in a different fashion (or just to see if you can put them back together without looking at the instructions sheet).
Once you've started on that route, it is all but guaranteed that you'll be hooked, probably for life (the model in the photo was a gift for me, from me, just last week). And if you are to build anything at all either without looking at the instructions, or a completely new design of your very own, then you have to exercise your imagination, and more importantly, be able to reduce a real world (or a fantasy!) object to it's very essence, one that can be expressed with a limited set of LEGO bricks at your disposal. And remember, you are very likely to have a really limited set available. Most likely it will be a combination of a few simple boxed models. If you're lucky you'll have a smaller or larger generic brick set box available. It is, however, extremely unlikely that you will have absolutely every brick LEGO ever made available. You will have to use your wits and imagination to manage with what you have.
I believe this is one of the best ways for honing your analytical skills. A fun way of learning how to see through bells and whistles and realise the essence of an object. LEGO allows you, no, forces you to make things as simple as possible, but not simpler (Einstein would be proud of it, I'm sure). Once you have your basic design you can, and probably will, embellish it with all sorts of decorations and unnecessary bits. But, this you can only do after it's finished. LEGO discourages you from getting lost in detail of decoration. Yes, once you've succeeded in the basic model you can easily pull it apart and then back together with bow ties all around. And you should, because you deserve to revel in its beauty and your own workmanship. But that comes later. First you raise and nurture a forest, then you allow yourself to admire individual trees, and even prune them to your liking.
For those in the know, a note about software-only LEGO solutions. Yes, I know they exist. Yes, I think they are cool, and useful. But no, I would not recommend them to general public, especially not kids just making their first steps with LEGO, regardless of how computer literate they may be. The main reason for this "Luddite" advice is that the pleasure of making something with your own two hands can never be rivalled by completing a model on the screen. You need to try it to know exactly what I mean. Then, there is the issue of absolutely every LEGO brick ever produced being at your fingertips, or rather in your LDraw palette. As good as it sounds it will rob you of the mental exercise of finding a solution with a limited set of building blocks. It is not only good exercise and a learning experience, it is also immensely satisfying once you find a way around limits of your stock.
Software tools do have their uses. Maybe once you have come up with a wonderful design you want a handy way of re-creating it with just the right colour bricks, ones you may not in sufficient supply. You get your model into computer and it will happily order all you need directly from LEGO. Or you may decide that for your model to be perfect you absolutely have to have that funny-shaped brick missing from your set. Fine. Go look it up and order it, but do build your model and put it on the shelf for all to admire. Then, when a new idea comes along, take it apart and build something new. And put it back on the same shelf. Looking at on-screen rendering of a model, no matter how perfect is no match for picking it up with your own hands, and having a good look. Even the fact that you risk dropping it is a good thing! It'll make you build something again out of that pile on the floor, and I bet it won't be the same. On the computer it's too easy to just load a file again. Do keep the files of your designs, by all means, though, but only so you can build them with real bricks again.
Finally, if there's one thing I'd like you to take away from all this: make your children play with LEGO, they usually don't need more than a nudge and a a few started models; after that they're likely to come back asking for more. More likely than not they will continue coming from more for decades to come. But more importantly, they will have been armed with mighty x-ray glasses to see the world around them for what it is, and not just what it looks like.