Suggestions

I like to give every section of track (spur, lead, siding, etc...) names and/or numbers. If you're modeling a prototype, you may be able to find these in operating diagrams. You could also add length in scale feet.

"give every section of track

   Yeah, Clic or Spins or similar books are nice reference for the way it's done on the prototype. I'd also give the staging and continuous runs a name denoting what destination they represent  such as Houston instead of south staging. Mile posts would also be handy to give operators some reference as to how far apart the various modeled locations are imagined to be, and to locate special features such as detectors or speed restrictions....DaveB

Prototype example

I scanned my prototype's schematic, then modified the track lengths (below).  I also added notes about clearances between various points (e.g. "840' - Linn to Locust") to clarify what would fit while switching, meeting other trains, etc.

In Council Bluffs, I also removed a couple tracks due to scene depth, but all changes were really easy to do in Microsoft Paint.

So based on the prototype, in addition to the track names and mileposts suggested above, I'd also add street names, direction indicators (e.g. "East to Chicago", "West to Council Bluffs"), and, if a track has multiple spots, indicators of their location (e.g. "Harlan FSC Spot").  I'd also second Joe Baker's suggestion about adding the track capacity in scale feet (or perhaps meters for your prototype) rather than a number of cars.  In my opinion, anything we can do to make our operators have to think like their real world counterparts is a good thing.

Dispatcher maps

Technically dispatchers are only interested in what they control.  So the schematics they use only show main tracks, sidings, controlled switches at junctions and manual interlockings.  They do not show industry tracks, automatic interlockings or yard tracks.

The dispatchers have access to the ZTS/CLIC charts and profile maps and other types of diagrams, but they dispatch off a schematic with only the main track on it.  Most people don't believe that a dispatcher panel won't show anything for an automatic interlocking, but its true.  There is nothing a dispatcher can control, so there are no controls so there is nothing on his diagram.  At most is just a line crossing the main track.  If you get an employee timetable that has track diagrams on the subdivision pages, the dispatcher will be looking at something very similar to that (the dispatcher's diagrams are not to scale by the way).

The ZTS charts have track names/numbers and may have major streets.  They are primarily used by the crews.  Local crews/divisions may produce even more detailed maps that show gates, loading dock locations, etc.  Profile maps generated by the engineering department show bridges, curves, grades, crossings, culverts, signals, derails, etc.

Differences with smaller prototypes?

Thanks for the clarification Dave.  Excellent point.

On the IAIS and perhaps other smaller roads, I wonder if the DS requires more awareness of the local switching that each train will need to do, as they include notes on it in their shift turnovers - in part because I believe they'll be the one calling dogcatch crews if the first crew dies.  I take it that's different from the class 1s?  Given that those notes often include industry or yard track names/numbers, I included schematics such as the one shown above in the info my DS would use, but you're obviously right that that level of detail isn't necessary in their primary role.  I should have clarified that.  

For me, it was also a matter of simplicity.  I just used the same diagrams for my DS that I display on the fascia for crews.

De facto Yardmaster

Probably on a smaller railroad the dispatcher is a de facto yardmaster.  Once again on class 1 the dispatcher knows about the industry tracks and has access to the detail maps, but what he uses to dispatch from is the schematic.

Technically if you go back to the train order days the "map" was the timetable schedule page.  The dispatcher didn't use any graphical image of the railroad.  It was all text.

If the model dispatcher is also used as a de facto station agent and yardmaster then yes they will need the detail diagrams to do the additional jobs.  If the dispatcher is solely tasked with dispatching then not so much.

Dispatcher map

Smelter track layout

A bit more work and the smelter track layout is starting to come together.  This will be a large traffic generator on the layout, I may have to consider running more than one train per session to the smelter.

The cyanide/toxic unloading bay is a new addition based on an email from Tim S. that they used to get bagged cyanide briquettes in boxcars for the smelter.   That should start a few conversations when the yardmaster reads the manifest...