Debian image comes with QWERTY keyboard installed by default.
This gave me some trouble for logging the first time I booted my Raspberry Pi.
Logging with name pi is no problem.
However, entering default password 'raspberry' with AZERTY french keyboard was no use.
Then I realized that I had to press following letters : 'rqspberry' for letter q on french keyboard actually sends 'a' letter using default keyboard map.
Once I was logged I edited the following file using nona editor :
nona /etc/default/keyboard file (remember here to strike 'q' key too instedad of 'a'!).
It was simple to place "fr" in appropriate field and then save Ctl O and exit editor, then reboot.