3.) Keep liquids and food away from your laptop. Liquid spills can easily kill a laptop. If food crumbs and other crud fall into the keyboard, carefully support and turn the laptop upside down (while it's turned off) and blow the keyboard out with gentle blasts of compressed air. Be careful, though; compressed air from a shop compressor or local truck stop can be powerful enough to blow the keys right off of the keyboard. Stores like Radio Shack sell cans of compressed air (they call it, "Dust Remover") that are fine for this purpose. Be sure it's air only, though, without any added lubricants or cleaners.
4.) Do not use detergents, cleansers or other solvents to clean the screen, keyboard or other parts. All you need is a soft, slightly water-moistened cloth, preferably cotton. Do not press too hard on the screen, especially if it is turned on. Gently wipe down, rather than scrub dirty parts and you'll be in good shape.
5.) If you travel with your laptop and it is subjected to fluctuating temperatures, always allow it to come to normal room temperature before turning it on. Doing so can prevent condensation from forming inside and damaging internal components. Don't leave your laptop in your car during hot or cold weather.
6.) Take care of your laptop battery. When you first get your new laptop, and the battery becomes fully charged, run it all the way down to zero and then recharge it; do this two or three times in a row. After that, use the laptop solely on battery power, running down the battery at least once a week, rather than leaving it perpetually connected to the charger. These methods can make the battery last longer, and, I am told that they should also be used on newer, more modern lithium-ion batteries. Even so, be advised that laptop batteries usually only last about two or three years before giving out completely.