where to live (New Delhi)

hello everybody, i am researching the ways of living in New Delhi, we might move there but unfortunately i do not have any idea of the city. would you help me by telling me in which areas do the expats live and simply why. And which real estate agencies should i look for. I would love to live in a big, nice compound, with all the amenities and close to food markets, green markets, shopping malls, hospitals,would i find them? Am i asking too much :)
many many thanks in advance
fusun