During this short trip you can see all the major landmarks of Dubai and Abu Dhabi.
Just start your engines on ramp 15 at Sharjah Intl. Airport tkae-off and turn to the South-West. Follow Sheikh Zayed Road that will guide you all along to Abu Dhabi and see all the major landmarks on the way.
You will need a few add-ons to have all the fun of the sight seeing, but make no worries, you can choose from both freeware and payware ones (see below my recommendations).