For some levels the map may just be a quick sketch with a few boxes and some notes, for others it's a series of detailed elevation drawings detailing dozens of rooms. In creating a map I'm also planning out the route of routes the player can take, and so I then might come up with some puzzle or subquest ideas for the level as well. I then march off to the design meeting to fight for content. As well as coming up with some cool new ideas for the level we will invariably look at schedules, weigh the value of a given detail or event against the art time it would take and what that time could be spent on elsewhere, and a revised plan is made. Once it has the collective seal of approval it is passed over to the level designers who then go about prototyping and building the level.
Questions always come up as the level is being built.
Do you want a blade in the wall or a cloud of gas- that kind of thing. Sometimes serious problems come to light only after we have a model partially constructed. In Lenele for example, we wanted the palace to show signs of having been a fighting castle centuries before. The idea was to have an old castle that has since been renovated and upgraded to a more luxurious palace that still shows signs of its past. That old castle look obviously must come from the architecture so we hit the books and looked for inspiration.