Browsing through a well-stocked hobby shop will give you a ton of ideas. You will see the wide range of products available in the various scales, including structures and detail items, as well as the trains themselves. You will be able to see models of trains from several eras in many road names and paint schemes, which will help you determine if you would like to model a specific railroad, era, or area. Talking to a knowledgeable clerk and other hobbyists will provide more ideas and guidance.