The train tracks arn't so hard once you figure out the trick.. You know how to put textures on your levels right? (select your texture of choice and right click to paint.) Well if "track" is highlighted then the track texture is superimposed over whatever texture you are currently using..
Well, actually half of it is.. You need to apply the track texture to the blocks either side of the center line.
Just remember to set the "edit forward" and "edit back" values to 0 or all blocks along that (z)axis will have the track applied to them