Getting Started
Some thoughts and recommendations to help you get started in model railroading:
1- The SPACE AVAILABLE for the layout. Consider access requirements. Think about your reach and determine how wide each section can be before a "pop up" or access port is required.
2- How much railroading do you want to model. Could be a long/narrow switching interchange... could be a square layout with one purpose (serving one key "business"). Could be multiple business/multiple railroad companies serving the businesses.
3- Scale... based on 1 and 2, you can determine what scale you will choose for your model train. obviously you can model a lot of railroad in Z scale in a fairly small space, and at the other extreme, modeling in G scale usually requires an outdoor layout.
4- Actual Size... as you get close to selecting a scale size for your railroad, consider the actual size of the cars, track, wheels, that you will be comfortable working with. Z gauge requires a very steady hand and often a "ramp" to get the tiny wheels on the track. All the details (Z gauge) are very small and are best appreciated close up. G gauge often is selected for garden (outdoor) layouts. Many areas will require the owner to kneel on the ground to take care of track maintenance and derailments.
5- Visit... your local hobby shop and see various models up close thinking about the space you have for your railroad, the amount of railroad "empire" you will be modeling and which scale trains are most comfortable for you to handle.
6- What are others doing? It can be even more fun if you locate others in your community, who are beginning model railroading or already have layouts you could visit. Seeing what they have done may helpful to you as you plan your railroad.
7- Get Started Today... do some up front planning, visit a hobby shop, visit model railroads in your area... and get started with your own model railroad.
Other websites on this topic:
National Model Railroad Association (NMRA)