* Here are the buildings you need in order to get contracts 
rolling in: a passenger terminal connected to the main road, 
a plane stand near the terminal's gate area, a control tower,
and a runway. You'll want to add maintenance buildings, 
parking lots, airport administration, and a fire station as
soon as you can afford to do so. 

* If you can't find the control tower on the Build menu, don't
panic. Some buildings aren't available until later in the game.

* Most contract offers are intentionally low, so you can usually
get away with sending most of them back at least once and 
negotiating for a better offer.