Lionel - Manufacturer of “O” gauge trains
MTH - Manufacturer of “O” gauge trains
Atlas - Manufacturer of “O” gauge trains
OGR magazin - "O" gauge railroad magazin
RailPictures.net - A very extensive bank of train pictures
UP steam shop - Union Pacific owns and operates two of the biggest steam locomotives still in operation to date. They have a 4-8-4 Northern, cab number 844 and a 4-6-6-4 Challenger, cab number 3985. These two engines make excursion runs usually through the summer months making stops throughout the US. You can check their schedule to see if they are going to be making a stop near you.
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.