Deep sky observing is done in the dark. Well, almost. You will need some light to read the star charts, make notes and find your mug of hot coffee. A normal torch, useful during a power cut, is unusable at the telescope. Astronomers traditionally use a dim red flashlight because red light has less effect on night vision.
It is easy to make your own night-vision torch. Simply place sufficient layers of dark red cellophane (used for gift wrapping) in front of the torch, thereby cutting down and filtering the light. I slip a red water balloon over the layers of cellophane to hold them in place. You can also paint the bulb with red nail polish for a more permanent arrangement. As a guideline, if you can see the torch light in daylight, then its still too bright.
Because of the notorious nature of human memory, you will need some way of recording your observations. At the telescope, a pencil and writing pad on a clipboard works well, as does a Dictaphone or tape recorder. I find using a small Dictaphone easier than writing descriptions by hand, partially because my handwriting is illegible but mainly because it is more convenient and allows greater freedom of expression. For sketching, a dark pencil, eraser and clipboard are useful, as well as sheets of paper with pre-drawn circles representing the field of view.
Green laser pointers have become an indispensable tool for astronomers giving a guided sky tour, and are very useful for telescopic observers for locating and pointing out targets of interest. Unfortunately, incidents of irresponsible laser use have occurred. The ASSA-Pretoria Centre has guidelines for the safe use of lasers.
“The palest ink is clearer than the best memory.” (Chinese proverb)