For domestic flights you should arrive at the airport at least 90 minutes prior to your departure time.
For international flights it is preferable to arrive 2 - 3 hours before the flight is scheduled to depart.
Please note that there are special security procedures in some airports that may require you to be at the airport earlier. That is the case for departures from cities like Tel Aviv, Bamako, Caracas, Conakry, Dakar, Djibouti, Lagos, Nouakchott or Ouagadougou and for direct flights to the US.
For more specific information, please check your boarding pass. Timetables and meeting places for charter flights will be included in the documentation of the journey.