Thanks for the comment Murtzuk,
I find that the best way is to keep things as simple as possible. For Nightshots, my simple rule of thumb is to set the Aperture to F8 and let the camera work out the exposure times. ISO should be kept as low as possible, 100 to 200 is ideal. A tripod is essential for nightwork, and setting the self-timer to 2sec or using a remote release also helps to eliminate camera shake. I shhot in RAW and set the white balance to either Auto or Daylight for the most accurate colours.
Hope this helps.
A few more for your perusal...
Cheers,
Martin