The number one thing everyone should be doing to prolong the life of their computer is to clean it. Physically cleaning the computer not only make your computer more pleasing to the eyes, but also keep it running nice and cool.
The most common way to clean out computers is the use the air cans. These air cans do a good job of blowing out all the dust that accumulates in your computer. Be careful when using air cans and follow the instructions. Make sure the computer is power off and the power cable is unplug before you begin cleaning the computer. Do not shake the can, spray it upside down, or hold the trigger for long periods of time. These air cans work best when done in quick bursts. Use of spray cans will indiscriminately blow dust up in the air, so I would recommend you take your computer outside and face downwind so the dust don’t blow in your face. Covering your face is also recommended.
Some use vacuum to clean out their computer as well. But because vacuum generates a lot of static electricity, I don’t particularly recommend it. I limit my use of vacuum to keyboard, mouse, and other exterior surfaces that would not be influence by the static electricity. For everything else, I would use air cans instead.
Limit the use of damp towels, or any other wipes (wet or dry) to the exterior only. Remember, water and electricity do not mix. Wiping the inside a computer with a towel can become dangerous as you might knock into things and damage them. Try keep contact to the interior of the computer to a minimal.