Hi Jeff--
Let me reiterate looking at some of those model rail-roading how-to books---they cover a lot of different things and many of the tips should be useful to you.
if you have no model-making or miniature painting skills, I do suggest starting off with small pieces and display items and mastering them first. Working out the hand skills with smaller things makes tackling the big project less frustrating, and will likely be more successful across the board. Patience, and a bit of planning, are key here to making an attractive display.
I don't suggest using real rocks for mountains, simply because of the weight issues. Instead, I would suggest building basic forms out of scrap wood, covered with chicken-wire and then paper-mache. Then you can add dirt using white glue, small rocks, lichens for bushes, scale plastic trees etc.
using chicken-wire/paper-mache allows you to have some flexibility in the landscaping......because you can form ledges and plateaus to your needs.
Simple, simple tip: get some 500ml sour cream tubs, empty, clean, invert them--paint them COBRA blue or slate grey.....get some COBRA stickers and boom, you have instant COBRA bunker-pillboxes that you can position anywhere on the display. If you want Joe versions, paint Olive Drab Green, and deco with a Joe or US Military insignia. Paint with Krylon colours for durability. You'd just need a couple of these in place to add some visual interest, along with the afore-mentioned model rail-road deco.
I suggest, for structures, getting for foam-core board ( Michaels art supplies have it for reasonable price). Its used for architectural ( and toy) mock-ups. You can cut it easily, glue to it, paint it--and general work it to your needs. I suggest building some VERY simple structures to get the hang of the material before building something ambitious.
Example: just a two-part corner of a ruined building or wall. Bottom parts and adjoining corner can be straight, top side and ends can be crumbled, rough-hewn.
Build it on a base about 3-times its size, add dirt/debris using white glue--paint, weather and deco as needed. It'll get you started on many of the skill-sets you'll need for the big project itself, and can be worked in to the diorama as you go.
Depending on your theme for the setting and can construct all kinds of nifty things from scraps. Thread spool can serve as fuel drums, drinking straws can become piping or wiring trunks, or even things like poles for lamp standards. Those accordion flex-straws have all kinds of used. Plastic fruit baskets--like you'd find strawberries in can be used for mesh, or fencing. With foamcore and items like those just mentioned you can build gantry and industrial structures and avoid the use of expensive Plastruct parts.
Best advice: doodle out what you have in mind, or write out a list of what you would like to have......then break-down the objects visually in your lists.
Fore example: If you want a COBRA outpost, with bunkers and a landing pad, you can figure out that you need certain materials for each item. Some have just been mentioned here.
But do take a look at some of the books out there, because they can spark some great ideas.
One last thing:
http://www.dioramadreams.com/This website is from a buncha pros and these gallery pages specifically should give you some ideas:
http://www.dioramadreams.com/galleryD9.htmlhttp://www.dioramadreams.com/galleryD11.html http://www.dioramadreams.com/galleryD13.htmlEnjoy.
