Regarding night photography, and assuming you can put the camera on a tripod or a stationary object: if your camera has a manual mode, set it to manual and then bring up the options (on my Canon, this is done by pressing FUNC/SET in the center of the 4-way ring).

• Set ISO. 100 is fine. On my camera, using 50 will significantly reduce "grain," the tradeoff is that longer exposure times will be required.
• Set the white balance to an arbitrary setting of your choice, such as Daylight, so the camera doesn't get to interpret the color of the light too radically.
• Set the shutter release to a delay setting, like 2 seconds, so you can push the shutter release button and get your hands off the camera so you're not shaking it while it's shooting (this presumes the camera has been set on a stationary object).
• Set the color effects to OFF. Shooting in black-&-white is another option, particularly if you're depicting different lights that have much different color temperatures (e.g. halogen and HID).

If your camera has manual focus, then it may be worthwhile to manually set the focus to, say, 5 meters or further. I often zoom the camera in a bit, too, because that narrower field of view represents what I see when riding.

Now that that's all done, you can manually set the exposure time, and take a few shots to see what exposure time will come out looking true-to-life compared to what your eyes see. Optionally, you can adjust the f-stop setting (lower f-stop = more depth-of-field blurring, but allows shorter exposure times; higher f-stop = less depth-of-field blurring, but requires longer exposure times).

Consult your camera's manual if you're not quite sure how to get at the settings