The most common kinds of wear are perforation damage, base scratches, emulsion scratches and breaks. Perforation damage is usually caused by either a malfunctioning projector, a mistreated projector, or a projector that has lost its loop. Base scratches appear as black lines and are on the side away from the emulsion.
Always keep the film path on your projector squeaky clean. The most common problem with long term storage of film is color fading. With B&W film you only need to worry about base degradation. Some film stocks fade very little, and others fade severely. Generally, cyan (blue-green) goes first, followed by yellow, ultimately leaving only magenta. Heat is the main accelerating factor. The quality of processing also affects it, prints from some labs always fade severely, others hold up much better under the same storage conditions.
Keep film as cool as possible. Never store film in an attic. Try to keep films below 60 deg. F as much as possible. At the extreme, freezing film will preserve it almost indefinitely, but care must be taken to prevent condensation on the film.
Smelling vinegar indicates a breakdown of the acetate base. When deterioration occurs, acetic acid vapors are produced, creating a distinctive vinegar aroma. The acid produced accelerates the process. Keeping the film in a sealed can traps the vapors, accelerating it further. This causes the film to warp, shrink and become brittle. High humidity and high temperature speed the process. Never store films (especially acetate) above 50% Relitive Humidity. Air conditioning units help reduce humidity, and stand-alone dehumidifiers are readily available. Extremely low humidity isn’t good either, storage below 20% Relitive Humidity can make the film brittle.
Cleaning film: Never clean film with water or a water based cleaner. It is best to use a cleaner made for film. I usually use Filmrenew which is a cleaner with lubricant and conditioner. It is relatively cheap and can help warped or brittle film. Naphtha can also be used, as can pure alcohol, avoid rubbing alcohol as it often contains water. All of these cleaners must be used under adequate ventilation, as the fumes are hazardous. Film cleaner can be applied with a clean soft cloth such as an old T-shirt.
Try to digitize and convert your film to a DVD as soon as you can. It is possible to color correct, remove black areas, and add background music when you do convert your film.