They were better than no directions.I'm not sure these were the best instructions.
I'll note that my preferred mapping modes were developed from Moldvay-Cook D&D, then 2.5 years later, by Traveller... but Traveller at that time barely included mapping symbology, specifically for the subsector maps.
TSR was providing advice in Dragon, especially with the "Ecology of the ___" articles, but some of Gygax's dungeons make less sense than an LSD-fueled retranslation of the Nabokov translation of Alice in Wonderland back to English... (Roommates...)I recall some terrible dungeons where the oft talked about orc in a 10ft room guarding a chest is from. There is also the dungeons where orcs live down from the trolls and the dragon is just below them as well. Oh, we will just say that it was a mad wizard who constructed the place and charmed all the monsters to be there. Blah.
Jennel Jacquays (as Paul so you can find it via used bookstores) did do probably the single-most useful book on dungeons. I wish she'd get it back via the CRA and get it up on DTRPG, My dead tree is getting fragile. (The Character books were less useful, but still useful occasionally - They look to have been around a core rule system similar to WEG D6)I thought we have had several good threats on dungeons in the past. I seem to recall some stuff on Jayquaying the map and 5-room dungeons.