The helicopter pad is a special building available from the very start of the game. Here you can collect your townspeople's orders and fill them by sending off a helicopter loaded with goods. It takes some time for the order to be delivered after you've tapped Send. The number of orders grows along with your town. The coins and experience points that you get for filling orders help you level up your town. Keep an eye on the number of coins and experience points that you get for filling each order to better plan your gaming strategy. You can dump the orders you don't like by tapping the trash icon. It takes time for a new order to appear, but you can speed it up by using Township Cash.
Once in a while you'll get special orders that come with a unique reward. For example, Don Pacone will pay you Township Cash for any gems that you have, while Aurelio the jeweler will trade his gems for yours.
During in-game events you might also get some temporary resources as a reward for filling townspeople's orders.