Another experiment in abstract schematic style mapping. This one was done in Word, with "view gridlines" turned on, drawing shapes (text boxes for rooms), and then turning the gridlines off again. Background was added with Microsoft Picture It 9, but any basic drawing program could be used for that sort of thing, really (and there may even be a way to fill in the gridlines in Word to make a background; I need to look into that more).
The small grey boxes at certain junctions are doors. Because room IDs are merely overall descriptors of each room, I'd probably even leave them in on an online players' map. I didn't do secret doors, but I think what I would do for those is have the connector line extend out from the hidden room, but not connect with anything visible to the players. This would let me know where the secret connects, without revealing it to the players (assuming online fog of war). So I wouldn't even need to have two separate maps for GM/players.