Alicante airport has a new terminal building (completed in 2011) designed to make the traveller's journey as smooth as possible.
The check in desks are located on the 2nd floor of the terminal building. To find out which airline operates from which desk view the airline information here.
There are also six self service check in machines to enable Iberia passengers to check in and print their boarding passes.
You should typically aim to arrive at the airport 2 hours (3 hours for outside Europe) before your flight departs.