Online check-in for the flight is usually available in 24 hours before the departure on the site of your aircompany. The convenience of this is that you are able register for you flight in advance, choose the seat and print the boarding pass by yourself..
Before using online-registration make sure to specify the time of the beginning and the end of the registration in your aircompany.
Online-registration ends in 90 minutes before the departure.
For the passing the control and during the boarding you need to print the boarding pass. If impossible to print it in advance, you can do this at the airport on the reception desk of your flight.
If you have any luggage, hand it in at the reception desk of your flight before the end of the registration of the flight.
The registration ends in 40 minutes before the departure.
There is no need to check in on the reception desk if you don't have luggage and you have the printed boarding pass.