Sometimes you can't make a good shot because of the lack of light or poor quality of your camera. In most such cases you'll get a "noisy" picture. This tutorial will teach you how to remove this noise.
NOISE REDUCTION BY IMAGE AVERAGING Adobe Photoshop / Photo Retouch
This section compares a couple common methods for noise reduction, and also introduces an alternative technique: averaging multiple exposures to reduce noise. Image averaging is common in high-end astrophotography, but is arguably underutilized for other types of low-light and night photography.
Ray of Light Adobe Photoshop / Effects
This tutorial demonstrates how to achieve the look of "light rays" using Photoshop's Fractal Noise and Radial Blur filters.