There are many ways model railroaders set up the roadbed for their track. Roadbed is actually the stuff the train tracks are sitting on, but I couldn't remember a word for the stuff that you put the roadbed on. Unless you want to build a completely flkat layout, then you are going to need to build stilts and supports to keep the track in the air. Some of the ways people do this are: not doing it at all, some people put the roadbed directly onto ther terrain in the layout; cutting wooden templates of how the trtack is going to curve out of the table and supporting it with wooden supports; however, the most modern, and perhaps the eisiest way to do it is to take foam risers made by the scenery companies, and stack them on top of each other in order to get the desired track height. These are made in several different grade steepnesses and can be cut down or stacked to achieve the desiered height. As an added bonus they can be bent to the shape of the curves eliminating the need for hard math. Rejoice all ye lazy fools like me!!! Once these risers, wooden bridges, or whatever are in place you should lay down the actual roadbed. As this site focuses on the smaller scales I wont mention roadbed loyal to only the large scales. Perhaps the eisiest, and the fakest roadbed is the plastic premade kind that comes with starter kits, and as it is so easy to assemble I'll just keep my mouth shut. ANother type of roadbed that is comonly used is cork. Cork is my personal favorite. Cork comes in two strips that mnust be seperated and then reassembled with the beveled edges facing outward. It can be bent around most curves excluding only hairpins. When installing this roadbed use glue, most kinds work, to glue it directly to the risers. The third type of roadbed is relitively new and is manufactured by woodland scenics, the same company that makes the risers. This type is some type of foam that comes in a long roll and is installed in relatively the sam way as the cork. I don't really like this roadbed but if youy like it thats great. Well, that concluses the artical, I hope you enjoy installing that roadbed.