BERT,
first thing to learn is, how to assess pictures. You see a picture somewhere you like (on the gallery here, in a book, in a magazine, wherever - learn to be able to disassemble it. See how it was done, look for the lighting angles (two shadows means two lights.....etc)
You will noticce that MOST "night" shots have some colour in the sky - that means they weren't shot at night. They were shot CLOSE to night, but before it really got dark.
You have about a 20 minute window on a good evening (like Saturday or Sunday this weekend gone) where there is light in the sky, the remnants of the sunset if you like, where the sky goes from pale blue on the horizon (or still a little orangy pink) through turqoise in the main part of the sky to purple at the top...this is the first bit to go black.
You need to shoot in that window of opportunity where there is still some light/colour in the sky and before it goes dark properly. The street lights and other lights come on obligingly around this time too.....get to work fast. Use a tripod, set your aperture for somewhere between 2.8 and 8 (I wouldn't go below f8 unless you wanted something specific). Have the picture in your head BEFORE you go to shoot it - or work fast if you see one. The light doesn't hang around and by the time you have set up, shot a couple of 3 second exposures, the exposure has doubled.
That is the secret. Of course, if you shoot totally lit scenes you can shoot all night - save these for when the sky has gone dark and you can't shoot them any more.
The other thing is, don't try to shoot too much at one go - far better to come home with one really good picture than to try for 5 and have a pile of poo because of it. Lots of rubbish pictures are easy, I do it all the time! One good one is what you want - it will make all the effort worthwhile - so put the effort into that one, and don't waste it chasing loads of pictures that are going to dilute the result. This approach also gives you more time to work the scene - new ideas will occur to you as you are shooting something, so keepat it.
