It is not clear here what you mean for "night photography". Do you take pictures of buildings, squares, statues etc. by night? Do you want to take images in moonlight? Do you want to render that it is night? (If you don't include the sky in your picture, you can take picture at night and it wouldn't show that it is night).
This link has a table, down the page, with typical EV for night photography:
http://en.wikipedia.org/wiki/Exposure_value
I find EV 3 is a good starting point for something that is lit as a monument. More normal street illumination over buildings is probably around EV 2. Spot lights on statues etc. can arrive to EV 5. If you use B&W negative, for general street night scenes I think that EV 2 should give you something printable anyway.
I do this kind of stuff with slide film and use a spot reflected light metre. I basically never feel the need to bracket. I point the spotmeter on the highlights that I intend to properly render as a texture at 2,3 EV "above" the grey point that the spot meter gives me for that spot, and that is all. With negative B&W you can even do, as said, without light metre as you have a certain error margin.
As already observed, you can't mix in your picture zones with only star or moon illumination and zones with artificial light. If you intend to take landscape pictures under star light or moonlight, you should try to exclude artificially lighted places from your composition.
If you just enjoy going around downtown taking pictures at night (as I do, but in summer) you will find that exposure values are pretty much similar, most of the time you are in the EV 2 - EV 5 range. Probably very brightly lit monuments can arrive to EV 6.
Fabrizio