It is not easy to picture how the final layout will look. Even I have some problems as I change my mind on how things will be done.
Presently the layout consists of a main line with local traffic allowed and inner tracks that, if traveled in one direction, would eventually lead to the inner loop. A train can start at the intersection with the S.P.&S. and without changing tracks, travel three times around the layout to the inner loop. With strategically thrown turnouts one could keep a train on the outer loop, but that would be useful only for "runing in" a new engine or similar task.
In the picture above one can just see the outer track. The next track in can be reached by following the outer track around one turn of the layout in a clockwise direction. The next rack in accesses a possible future rail yard. It crosses over the track on the far right and ends right now. Work is yet to be done. The track on the right is part of the inner loop that would be reached if one continued in a clockwise direction around the layout. The Turnout just beyond the diesel leads to a "Y" required to turn engines around on this layout ... there will probably never be a turntable.
The present layout is all DC. It is not completely wired in a useable fashion but a single engine and its cars can navigate the entire layout. If you noticed, the civil war box cars are indeed smaller than the "modern" boxcars on the outer track. Most of the modern rolling stock has been obtained at model railroad meets and a few select local hobby stores. I am particularly fond of Vic's Hobby Supply on NE Broadway in Portland, OR. They are very helpful in the area of maintenance and scratch built items. A friendly staff, easy parking and best of all, no need to drive from where I live. See http://vicshobby.com for a view of the store. It's not much as a web site, but does have a couple links to N scale cars....
It's time to get back to the real work around here. God bless and happy training!