Either go to their offices and drop your resume there

http://www.qatarairways.com/global/en/offices/contactus_qatar_mainOffice...

or send it through the website

http://www.qatarairways.com/global/en/careers.html

Good luck!!

Regards!!

PS: If you want to try with other airlines working and operationg here in in Qatar try their website and apply on line.