My new Unit for my toddler (ages 2-4) sunday school class is called: "welcome aboard the traveling train!" I'm supposed to have seats set up like a train and I already have posters that they sent me that look like your looking out a window into a city. I'm also supposed to have a train station office so I can give out tickets at the beginning of every class. They told me I could use PVC Pipes to make it but I'm not sure what those are or how to make a mini-office in a little room. Please give me tips and info...a few pictures might help too. Please keep in mind that little kids will be in this classroom and I dont want them to get hurt. Also budget is minimal so something that can be reused in a couple of years would be preferable and something easy to assemble and cheap to buy would be perfect. It says to make an awning type roof, A wooden window and door may be nailed to the cardboard wall...what doea that mean? can you really nail wood to cardboard? do you need a special kind? thanx