To be safe, always clean with the materials that are recommended for cameras and take special care as replacing camera parts can be very expensive.
1. Thoroughly clean the exterior of the camera with a soft, dry lint-free cloth. These can be purchased at a camera store or you can use any chemical-free soft cloth you have available. Clean the exterior first to prevent dust and dirt from falling into the camera when you remove the lens.
2. Clean the mirror and the focusing screen gently with a can of compressed air (available from Dick Smith Electronics or Officeworks) or a Giotto’s Rocket Air blower (available at Ted’s camera stores). You can also lock up the mirror and clean the sensor with compressed air if it is required. Never touch the sensor or use anything on the sensor besides air. The sensor is only exposed when the mirror flips up during exposure. While you need to clean the focusing screen and mirror regularly, it is unusual to have to clean the sensor. Since replacing the sensor is very expensive you should take it to a camera service specialist if you are not sure. Usually the camera and mirror will only have dust to clean off. Hold the camera body face down when cleaning so the dust will fall off. If the mirror is smudged you can use a small amount of lens cleaner and lens tissue to clean it.
3. Clean the front element of the lens with air to remove the dust. If the lens is smudged use lens tissue and a small amount of lens cleaner to clean off the smudges. Make sure you remove the filters and clean both sides of the filter as well as the front of the camera lens.
4. It is very important to clean the rear element of the lens. The light is more focused when it passes through the rear element and dust on the rear elements will attract heavier particles than the dust on the front element. Clean the rear element in the same manner as the front element with air and then lens tissue and cleaner.
5. Clean the camera back and top glass areas. Always clean the eyepiece in the same way you clean any lens. The operating screen and viewing screen are not as critical as the other glass parts of a camera, but clean them the same way as the lens. It is very important to be consistent in cleaning your camera. Never use any cleaning supplies that are not manufactured for camera cleaning. Windex and other alcohol-based cleaners will damage camera elements. Facial tissue and paper towels are manufactured with chemicals that could damage camera elements.