Best things to do: Enjoy the beach/water, tour the desert countryside, visit Natural Bridge, and visit the California Lighthouse. Try to go to a "local" restaraunt in order to better experience Aruba. The people are very friendly.
Quick Tips:
Know if you want to stay in a low-rise or high-rise hotel. Visit online bulletin boards to get a lot of useful information regarding food, entertainment, and lodging. Best Way To Get Around:
Renting a car more than pays for itself if you leave your hotel a lot. Cabs can be expensive if you travel from one area of the island to the other. Walking around, though, is very safe, at least to my wife and I.