Not a quick question at all.
I'd like to make some suggestions.
Firstly, search the archives of this forum. This question, and similar questions, have been asked before by newcomers to the hobby. Many members, myself included, have gone to some lengths to respond to such questions, to relate our experiences and to offer our advice. Spend an hour or two reading past posts, and you will come away much more savvy about what to do, and what not to do.
Secondly, don't spend a dollar until you have spent an hour reading up on the hobby. Don't spend ten dollars until you have spent ten hours. And so on . . . give yourself a couple of weeks or months deciding what you want to do, where you want to go, and what you want to buy. Thay way you will avoid many of the most common newbie mistakes, most of which stem from impatience. Diving in head-first is an invitation to disaster. Research and planning will result in an enjoyable, operator-friendly model empire.
Model railroading is more than "just a hobby". It incorporates many different aspects of science and math as well as art — architecture, electrical and electronic engineering, model building, machining, painting backdrops, plastering hills, building bridges, and so on. It is almost infinite.
Before you rush out and buy a trainset, ask yourself some fundamental questions that will help you define your interests:
1.) What era do you want to model? Steam? Transition era (1950s and 1960s)? Second generation diesels (1970s and 1980s)? Modern (1990s to date)?
2.) What railroad/railroads do you want to feature?
3.) Do you want to run passenger trains or freight? Or mixed consists?
4.) Are you interested in continuous running, point-to-point switching, or operations? you may not be familiar with these terms, but they are all particular aspects of running a model railroad that appeal to different people. Check them out. Most people settle on a little bit of operations with some continuous running away from the action.
5.) What kind of geography do you want to model? What kind of terrain, what industries, urban or rural, mountain logging railroad or a subway?
Then once you have some ideas, start to focus your reading. Find out what locomotives and rolling stock are available, and from whom, that fit within your area of interest.
That's the first hurdle — defining what you want to do. the next challenge is determining what you can do.
The are three main questions to be addressed here:
1.) The first is rather obvious — what is the missus' attitude? You may have to help her realize that model railroading is more than "playing with his toys". You have to win her over to supporting your hobby, lest you come dancing through the door one day, happy as a clam with a super-duper brass Hudson retailing for $2000 that you were able to scoop for a paltry $750 — and catch a frying pan on the forehead.
2.) That brings us to the next question — your budget. Model railroading is expensive. A good (plastic) locomotive is $200, a good freight car ranges from $20 for a kit to $50 for RTR (ready-to-run = some 14-year-old in China built it for you). A turnout, with motor and switch, will run $35, and you may end up with dozens on your layout. It's worth mentioning, so as not to scare you off, that such a layout is built over a period of several years, but it can amount to a significant piece of change.
3.) How much space do you have for your layout? It is common for beginners to set up on a 4x8 sheet of plywood, but that is really not enough space for an HO scale layout. HO scale seems small, but trains are not. I have watched unit trains of 120 grain hoppers roll by at a crossing. 120 hoppers, with locomotive and boosters, are going to be 1200" front to back — 100' if you will. that's a pretty long train to put on a sheet of plywood! I am maybe stretching the point — we all compromise with "scale compression", and 20 or 30 hoppers give the same impression visually, but them's the facts. In HO scale, you don't want a train table. You want a train room. And FWIW, N-scale is no less expensive, has half the detail, and carries with it half the compromises in terms of space limitations.
Those are questions to help you determine what is possible, given your situation.
If you can answer those two fundamental questions — what you want to do and what you can do — and can resolve one with the other, you are well on your way to starting the adventure of a lifetime.
And if you've gotten this far, forget El Cheapo trainsets. Buy quality locomotives and quality rolling stock, just a few to get going. You get what you pay for, as long as you're dealing with reputable dealers, and you will quickly be able to see the difference in quality. There is no "best" manufacturer — there are some to avoid, but the rest are pretty well even. Each kit or model must be assessed on it's own. All have weak points and strong points that differ, and it behooves oyu to determine which one you like best, based of detail, ease of assembly, paintwork, reliability, and price.
Also, lay down a simple loop with a couple of sidings to get going, to run some trains while you develop the rest of the layout and keep your interest up.
Next item of business is a track plan. There are "cookie-cutter" track plans available from a variety of sources. Avoid them if you can and let your own plan evolve. Kalmbach has a book by the late John Armstrong, "Track Plans for Realistic Operation", that will guide you through getting the most from your available space. It is the best book you will ever find on the subject, and an indispensible resource while you develop your layout — the best $20 you wil ever spend, I promise.
I got into trains four years ago, after decades of modelling aircraft and tanks. I made all the newbie mistakes with my sheet of plywood, and my first layout became the backstop for my dartboard. I speak from experience, and I hope my comments have helped you get a handle on how much is involved in starting out.
Cheers
Scott Fraser
Calgary, Alberta