The Keflavik airport is the biggest one in Iceland, and it is considered the main connection between Iceland and the rest of the world. The building has started in 1942, and within a few months the first 2 runways were usable. In the following years there were a few re-constructions and upgrades, and the north building and the south building (not separate terminals) were enlarged. Currently the airport has two asphalted runways each measuring more than 10.000 feet. At this moment the airport can handle more than 2.3 million passengers per year. There are some plans of adding a new runway and constructing a new terminal in the next 3-5 years.
The airport has three places in which the passengers can park. P1 and P2 are for short term parking and are close to the terminal, while P3 is for long term parking and it is a little further. There are also specific places for bus stations, car hire parking and taxi parking. The map with these places can be found on the official Keflavik Airport. All the payment should be made in local currency, so you might be needed to exchange some money. If you want to get from the airport somewhere in Keflavik or Reykjavik, you can take a bus. There are two different companies which provide transportation. One is Flybus and other is Airport Express; each of them will take about 45 50 minutes to get to Reykjavik. They leave about 30 minutes after a flight lands.
Taxis are also available just in front of the terminal, or if you want to car hire, there are 4 agencies which have a branch inside the terminal. The internet access in not free, so you will need to visit an Internet Kiosk in order to get details about how to connect. In terms of shopping and dining, the airport has 18 places spread inside the terminal. You can find coffee shops, minimarkets with all kinds of souvenirs, gifts, perfumes and watches, and also shops with various snacks. In three words we can say that you will find everything you need.
Iceland is a beautiful country and I think everybody should visit it at least once in a lifetime. So save some money, take some time and visit this land of ice, but make sure your plane lands at the Keflavik airport.