It is traditional for the family, and in many cases the extended family to travel to the airport with whomever is departing – and so despite the fact that the airline schedule itself is relatively small for an International airport, you can multiply the numbers of seats by 5 or 10 to get an image of the departure and arrival areas.

Security is such that only bona fide travelers are allowed to actually enter the facility – so be prepared to show tickets and passport as soon as you alight from the van or taxi. There is inevitably a crush around the departure entrance, as family members either endeavor to get into the facility, or are just enjoying an argument – so keep documents close to you and in a firm and secure grip, as you should anywhere faced with a concentration of people.

Once inside the airport proper, it is relatively serene and well organized. You are faced with the usual array of departure counters, segregated lines etc.. There is substantial paperwork yet to be undertaken however – a departure form and a customs form, so have a pen in hand and be prepared to complete as you await check-in.

One tip here is if staying at or close to the Guatemala City Marriott, American Airlines have a check in office there (open until 6pm) – and all of this paperwork can be taken care of in advance.
Once you have checked in, you will be directed to a booth on the checkin floor (currently close to the entrance), where you will have to show your ticket and boarding pass in order to get the $3 airport tax (payable in USD or Q).

This will then be affixed to your boarding pass for checking later.
From that point on, it is a normal international departure process.