Hi...
Most people above have focussed on the fact that you aren't married....this really could prove to be a problem as living together without being married is illegal here.
There is a huge ex-pat community here - from UK, USA, Europe, South Africa, Australia and Asia.
The tax free salaries are good....career opportunities are good.
Cost of living is high...especially socializing as all restaurants serving alcohol are only in four or five star hotels....ditto for bars/clubs. Plus cost for food, clothing etc in general is quite high here.
You can fly to Dubai for the weekend and people do. But you need to get an exit permit from your employer/sponsor every single time you do this. It can be a pain to arrange last minute.
Also if you are commiting to come to Doha it really isn't a good idea to focus on Dubai being your saving grace. Otherwise you may as well just try to find a job in Dubai or Abu Dhabi.
It is much more conservative here than Dubai but not as strict as Saudi. I am a single female living here and feel very safe and can comfortably go out alone. Also woman are not required to cover their hair here - it is appreciated if knees and shoulders are covered and if females wear short shorts or mini dresses and strappy vest they do get stared it....by qatari's and labourers alike - it attracts a lot of attention you don't need.
But your main big question to your potential employer has to be about the fact that you are not married. Also if you are not married she can not come in under your sponsorship and would have to find her own sponsor. And without a sponsor you can not get a residence permit or work. Good luck with it all....