On a busy day your garage door may open and close 20 times, 
so routine maintenance is a must to keep it in good working order. After all, an ounce of prevention is worth a pound of cure. Regular garage door cleaning and maintenance will guarantee a great look and longer life of your door.
Appearance
Clean your garage door regularly with mild soap (like dishwashing detergent) and a soft bristle brush. Avoid using abrasive cleaners and very strong liquid cleaners which could damage the paint or cause delaminating. If you have a steel garage door, you can revive its luster by applying a car wax as it will protect against acid rain and dust. It is best to avoid waxing in direct sunlight to achieve better results. If there’s exposed wood, be sure to paint it.
Exterior Weather-Stripping
Clean the weather stripping around the frame and bottom edge with a good all-purpose cleaner. Lubricate it every 2 or 3 months with a Silicone-based lubricant to keep the stripping pliable. Never use a petroleum-based lubricant on weather-stripping as it will dry up and crack. It is important to let your weather-strip hang 1/2″ below the door base when you readjust your perimeter weather-stripping. If the weather-stripping is too tight, the door will not function properly. So if your weather-stripping has lost its flexibility, it is best to replace it.
Final Advice
Consider your garage door as an important part of your home. With appropriate annual maintenance, it will door will provide carefree convenience for many years to come. Ask a qualified garage door installer, to lubricate and adjust your garage door at least yearly. A check-up will insure he will lubricate all the above mentioned parts and perform any required repairs.