Well, here's the blast door invisible map. Thought it could answer to the "Look north" thing, but hmm...
http://lostpedia.com/images/0/00/Blastdoor001.jpg
I'm guessing the south building is The Hydra, seeing how big it is, and you can see it's not really part of the rest of the Island (you can see a sort of river, which would be the ocean). If this is the case, the bottom left building could be on a third island.
The top right one, would be The Hatch because it has a lateral corridor, which would be the Hatch window, John found.
The top left looks like it doesn't exist anymore. It may be the one where is hidden the Eyepatch man.
The two on the right looks like they were on construction when Radzinsky made the map.
You can also see some of the buildings are linked to some others. But if The Hatch is the northern building, then the map has nothing to do with the sentence on Mr Echo rod...