Prop up the back of the machine so the underside can get a half decent airflow. (My dad uses a Triangular Ruler, which works wonders)
Never play games with the laptop in your lap. Sounds silly, but with the combined heat output of the laptop under load and the natural heat from your body it is recipe for disaster.
Do not open any part of the laptop, doing so will very likely void your warranty making it very difficult to get any parts replaced.
If you travel allot, or live in a "high risk environment" (AKA Children) make sure you take out some form of insurance on your shiny new toy.
You can buy cooling mats/pads with built in fans to help keep it cooler, but I just use a breakfast tray when i'm using it in bed, this keeps the laptop off the duvet and helps stop it overheating.