I don't know about NASA's official preferred location if they have one at all, but the most considered locations (also by NASA) for a permanent settlement on the moon are, based on our current knowledge, the two poles of the moon.
At the south pole of the moon there is Shackleton Crater. It is one of the possible sites for a lunar base , in particular its rim. The Pole is almost permanently sunlight and thus one can sustain reliable solar power with very few solar arrays. This also means that the temperatures average at a more human-friendly -50°C, other than the huge temperature fluctuations you experience in equatorial regions.
The inside of the crater rarely to never sees direct sunlight, and it is believed that there might be a valid source of frozen water inside. Another advantage of this spot is, that it is proposed as a possible site for an infrared telescope, because the low temperatures inside the shady crater are ideal for infrared exploration.
At the north pole there is Peary Crater. It's advantages are basically identical to it's southern twin, Shackleton Crater.
A common limitation on both poles however might be solar wind, which can cause electrical charges on the surface of the crater rims. Those charges could harm or distort electrical equipment and signals, and erode the surface.
Of course, the other problems that come with the absence of an atmosphere will not be solved by those locations. There is no protection from meteors whatsoever, and cosmic radiation is not limited.
I hope this helps to give you a little bit of an idea of what the pros and cons of those areas are.
EDIT: To add to the answer of the question, the ESA has a concept (though not a definite plan, at least to my knowledge) up their pipes, considering the southern pole as the most likely site. It is their concept for a 3D printed lunar base. Recommend a look at it.