All the maps are based on German printed Topos. The maps scales are usually 1:1,000,000 but go down to 1:300,000. For example, the Eastern Front maps are almost always in two parts, (two scans) a north half and a south half. The Germans did a morning -"furth" (early) -map showing large scale movements and thrusts and some units, and an evening -"abends map showing final unit dispositions of German, Romanian, Italian, Hungarian, Finn, ect as well as Soviet down to Division.
As the war went on they began to only make the abends map showing both movements and units. NARA is only missing maps for the East for a total of 23 days of the entire campaign. Also some days they also have only either the morning of evening maps.
When you order the East maps they will right now be coming by months. So you CD will show as an example 1Jan43 M pt1, 1Jan43 M pt2, 1Jan43 A pt1, and 1Jan43 A pt2. Meaning date- M(movements) or A(abends) and part 1(north) or part 2 (south).
On some maps also are handwritten notes on weather, build-up of Soviet forces in rear areas, aerial recon data (like outside Stalingrad in Jan 43 indicating no break out attempts), German civil areas, and type written notes glued to the map on strengths of various Soviet units.
Of course for other areas and campaigns there are more details and more sub-units.
I am working on a complete date guide for each map set as well which Jason will post on the map order page