I owe a debt of learning to model rail-road people. It was at a rail-road hobby show that it first dawned on me the difference between collectors and hobbyists. There are collectors who don't necessarily ever even take their train cars out of the original package, and then there are the guys that build elaborate set-ups and actually run their trains. They go the same shows and are polite to one another, but they are entirely different species. I fit into the later group myself. But my toys have horse-power, carbide teeth, and make saw-dust of various sorts. (Come to think of it, I might also be a collector after all -a tool collector.)
Permit me to offer separate bits of advice to each species -starting with the hobbyists -if only because they are easier.
The Hobbyist's Work-Shop:
Building working railroad layouts involve structure -something to hold it all up, electronics -to make it all work, and a not inconsiderable amount of art & artistry -to make it all look realistic. Impresses the heck out of me. I offer only a modest suggestion and it has to do with organizing all the various little tools, materials, tiny people, paints, tree branches, goo to make lakes look liquid and a hundred other things that I don't know about. Put it all in an architectural drawer case. And then use it as the structure of your layout -to hold it up.
Actually, I lied about only one piece of advice for the hobbyists. I have a suggestion for the guys who work in real small scale. I know one model rail-roader that built an entire working -but very small scale- set up in my coffee table display case and kept the whole thing in his living room.
Preservation for the Collector:
Not sure what to suggest to people who never even unwrap their model rail-road cars and engines. For those who are not so disciplined in their collection -the guys who open them up and play with them just a little, I'd suggest you consider using desiccants and protection against the threats of light degradation, and maybe study up on archival materials.
Displaying rail-road models is easy. For starters, I make two different Slider Display Cases just for rail-roads -or they started out for such anyway. I've sold them to lots of people who collect everything from to shot-glasses to duck-calls. For a single very special model put it all by it's lonesome in a shadowbox.
So you may have noted above my ramblings on the differences between collectors and hobbyists. Model Rail-Road Scenery demonstrates this in spades! Is it art? is it engineering? Is it showmanship of the first degree? Yep to all. Have a look at lovely scenery -at 6/64th scale, or have a look at some wonderful HOW-TO. I like 'em both.
Come we now to International List of Scale Model Related Web Sites -This is an impressive site where scale modelers can share their favorite sites with others. It has excellent sections on rail-road modeling -organized by scale and topic. Most impressive.
This site has it all -both model and the real -check out Trains.Com
Chap named Terry Callahan has himself a great site on Railroad Modeling -all kinds of advice for both beginning and expert modelers.
This is a commercial site, but an excellent one. Check out Model Railroads.net.