I need advice on where to live in Edinburgh

Hi there I have recently secured a new contract which requires me to work in Edinburgh for Protected content . I have no knowledge of Edinburgh other than it being 'the most liveable city in the UK'. I will be working in the city, Fettes Row, and would be looking to rent a small apartment that is easy access to the city. Or is the city a good place to live?? Additionally, I'd like it to be in a friendly, vibrant neighbourhood... one with cafes, bars, restaurants (I may be asking too much here as I know Ed is quite small, so maybe easy access to them). I am single, so not a family neighbourhood thanks! I have already been recommended Morningside and I've been googling, but there aren't any sites that give the low down on the hip and happening neighbourhoods. Any advice will be appreciated. Cheers Sondra