Mark scans jpegs in, scales the photo, then draws over it. At least that's what he told me he did. That's why Al was shooting all of those overhead photos last year to update the records.
There are also two binders with the drawings in them. Skip had one, not sure where the second one is.
For my plans, I drew up a POFF, 3foot corner, 6 foot module, etc. using CADRAIL. When I plan a layout, I just copy as many as needed, then start laying them out. When it's done, I export the plan as a jpeg. I have to remember the track config. on the special modules to make sure the right ones get together.
Martin