In addition to getting a good laptop cooler(Vantec make excellent coolers). I have a model with a 4 port USB hub.
WHERE TO BUY - ONLINE STORE
Here is a great program that will work with many Dell models. I have it set start with Windows. I also have it set to have the fans run constantly since I never shut my laptop off and it rarely runs on battery.
Dell Inspiron Inspiron/Latitude/Precision fan control
Since my laptop runs 24/7, once a month I take canned air and blow the dust out of the CPU and GPU heatsinks. Blow backwards through the heatsink sink to start with since dust cakes up between the fan and the heatsink.
As for the AC adapter either get one with a higher wattage or place the adapter on a flat metal object. Since my laptop doesn't go anywhere, I have it strapped to the metal leg of my table.