Nice, cant get much better than Mayfair for a place to work.
As far as living goes it really depends on what sort of thing you are looking for...
A quick summary of some areas that I know:
* Camden (North London) -> Fairly cheap, very vibrant, lots of "young artist" types, very colourful
* Angel (North) -> Similar to Camden, slightly further out.
* Clapham (South) -> Cheap, but quite far out and transport to central london is not great. The northern line runs through it, but it is VERY busy during commuting hours... expect to have to wait for 2-3 trains before you can get on.
* Brixton (South) -> Near Clapham, its quite a rough area, but appeals to some people...
* Pimlico (South/Central) -> Posh area...
* Putney (South West) -> V nice area, quite chilled out, lots of young families, nice high street / bars etc, good transport to central via district line, not too expensive.
* Fulham (South West) -> Slightly closer to central than putney, more expensive and trendy.
* Chiswick (West) -> Quite similar to putney but a bit cheaper
* Kensington (West / Central) -> Similar to pimlico
The above is a fairly general description, if you want any more info on any area specifically then let me know... lived in london for quite a while so would be happy to answer any questions you have
G