The thing is don't try and cram everything into it. Your room is 9'x8.5' what you could do is run a 2' wide base board around the room with a lift up trap door like I have in Ballykay http://www.irishrailwaymodeller.com/showthread.php/1003-Another-little-corner-of-Ballykay
I would then put scenery on half the layout like an L shape and the other half I would leave with no scenery and have my sidings. You could then call a train up run it through the scenery section it then disappears back into the sidings and you call up the next train to run through the scenery section. As I said keep your layout simple if you try to cram every thing in there stations,sidings,buildings,towns,roads etc etc its then going to look toy train like