read this thread:
http://www.pprune.org/middle-east/46...ar-salary.html
http://www.pprune.org/middle-east/46...ing-qatar.html
Note that as a DEC you may get looked after alot better than F/O's, SO's etc
BUT you still will get worked hard!!
Chances are you will get accomodation provided, but at this stage there is a housing issue; however depending on your train of thought, co.housing or finding your own villa has its pro's and cons.
Good luck.