Check the site Bayt.com for jobs in Qatar...
you can register and post your resume there..
companies always look through it...
an dyou cna also look for various jobs..
They also email you almost daily.. about the various jobs which might suit your skills

Otherwise, you can alway sfind a buisiness directory or a yellow pages if they have it ... and starts sending to all companies that fall under the category of your choice...

all the best
DS