Operating steam locamotives
Abilene & Smoky Valley Railroad
Cumbres & Toltec Scenic Rail Road, CO
Durango & Silverton Narrow Gauge Rail Road, CO
Fort Wayne Railroad Hisorical Society
Great Smoky Mountains Rialroad
Steamtown National Historic Site, PA
Layouts I've surfed across
Model R.R. Scenery - This site has lots of very good videos, articles and information on building all kinds of layout scenery. Whether you are just beginning or even if you are an old hand at the layout scenery game this site is highly recommended for information and ideas.
Miscellaneous
North American Railcar Operators Association