Shooting images at night can be a technical challenge, but also can open up a lot of possibilites to you with regard to what you consider to be phtographic subject matter.
Just about any camera can shoot photos at night, so long as you turn off the built-in flash. Once the flash is off, the camera will do what it needs to do with the shutterspeed in order to try to get enough exposure, which means that it may stay open (exposing) for a long time. This in turn means you MUST have a tripod in order to hold th camera steady during this long exposure. What's more, when you are shooting a long exposure with your camera on a tripod, the action of you pressing the exposure button to start the exposure may be enough movement of the camera to make your image fuzzy even with the tripod. My suggestion is that you use the camera's built-in self-timer to fire the exposure without requiring you to touch the camera. Look in your camera manual to find out how to set the self-timer mode.
Here are some suggestions:
Some cameras like the Canon 20D,30D,40D will actually perform a special noise reduction process just after the exposure. What goes on, is that a second exposure is created which has no image on it. This second exposure is inteded to capture the "noise" inherent in your first image. Then, the camera combines to the images in a special way to remove the noise from your first exposure.
If you can get your camera to shoot a blank frame, you can do this manually by following these steps:
Another suggestion for reducing noise is by using photoshop plugins or other after-market software such as NeatImage.
Custom White Balance
In the above guidelines, I've suggested that you have your white balance on Auto. This works great for most situations, but sometimes, you may want to try custom white balance. Custom white balance will allow you to choose a subject in your scene that should be grey or white and have the camera calibrate to that instead of the entire scene as it does in Auto. This can give you dramatically different results, but can also add noise, so watch out.