Go online 24 hours before your flight and log onto your airline website. Most major airlines will send you an email the day before your flight offering this option, so logging onto the site should be a matter of just clicking on a link from there.
Click on the button or link to check in to your flight. You will be asked to fill out your information in text boxes to ensure that you have the correct flight.
Click on the button to check in to the flight. You will get a confirmation page as proof that you have checked in correctly. Print this page and bring it to the airport in case of the rare mix-up with the airline.
Follow the website's link to the seating chart of the plane to choose your seat for the flight. You don't have to go through this additional step, but if you want a window seat or hate getting stuck in the middle chair, it's a good idea to reserve a particular seat now.
Print out all acknowledgment pages and emails the airline sends you and bring them with you to the airport. Some airlines give you the option of printing a boarding pass, which will save you even more time at the airport.
Pass by the check-in desk when you arrive at the airport and go directly to the kiosk to print out a boarding pass if you didn't print one out at home. You may still need to stand in a short line if you are checking bags. Go through the security checkpoint from here and to your gate to wait for your flight.
