Car washing should be done regularly, perhaps once or twice a month. Things that are acidic or basic, like bugs, bird droppings, limestone drippings, or salt deposits should be cleaned off as soon as possible. Moisture collects in dirty areas causing corrosion.
A pressure wash is due every once in a while. The pressurized jets of water can take off dirt where you normally can't reach. The pressure wash jet should not be held too close to painted surfaces. The water pressure is sufficient to take off the paint.
Do not neglect your windshield or your wiper blades. Sand or harder dust particles caught in the wiper blades can leave scratches on the windshield when the wipers are operating
Waxing is as important as washing, even if you don't have to bother with it as frequently. A high quality wax job will stay on a car for three to four months. There is no such thing as a lifetime wax job. The wax is there to protect the paint, and will eventually wear away from environmental elements that would have previously damaged the paint directly.
A wax job every three months is okay. However, if your car hasn't been waxed in a very long time, it would be a good idea to have your car detailed first. They will use an electrical buffer to buff the car, removing light scratches, hard stains and other impurities on the paint. Then they apply a coat of wax. Once the car has been detailed, you can simply reapply the wax job every three months or so.
There are varying qualities of wax, so do some research and find a better quality one, preferably one with no abrasives. You will need a soft sponge, or a soft clean towel. The car must be clean and dry and should be parked in the shade. Read the instructions on how to apply the wax, and then work on one section at a time, like a door or the hood.
If the wax you are using is liquid, shake well before using. Start from the top and do the bottom panels last. There is always some dirt on the bottom and it will get on your sponge.
Make the layers thin and even. Once done, allow the wax to haze and then buff to a perfect shine with a clean soft towel. Rotate the towel frequently to use clean parts of the towel.
You're almost done. The last bit is to remove any wax that might have gotten on non-paint surfaces. The wax will stain rubber or plastic white.