Check the various newspaper websites (Qatar Times, Peninsula, etc) for an idea about prices etc. I assume if you're working on the Corniche it's in the main business area - it's probably the most expensive for housing but in some ways fairly convenient depending on your lifestyle.

Again, it depends on what you want/expect/need - building with gym/pool? Building with good security with good maintenance? The ads in the newspapers will give you some agent names and numbers - can't help there because my employer provides my accomodation - might be able to advise on areas and commute times.
Signature line > "You can't fix stupid"