Re: nightshots w/ coolpix
Automatic should get you very close to what you want, but I would recommend turning on the Noise Reduction mode if your camera has it. I have an older Coolpix and it gets very noisy over about 1/4 second so NR helps a lot.
Once you have your shot, check the histogram to see if it's really what you want and adjust from there if needed. Surprisingly, even though there is a huge amount of contrast in those types of shots, most cameras get very close.
Re: nightshots w/ coolpix
For night photos a Tripod is a MUST.