One extra comment: the setting plays such a vivid role in the novel that it could be studied for it alone--as the world of the characters, it is almost a character itself. The novel begins with a description of the setting: the day is cold, the clocks strike thirteen, the wind is vile, and a swirl of gritty dust permeates the air. The hallway smells of boiled cabbage and old rag mats, a picture of Big Brother Watching You hangs on the wall, the elevator doesn't work. This description assaults all of our senses, providing the groundwork for everything that follows.
There are several things stated in the book both about the characters and about the setting. This is a very general question.
Setting is spoken of when Orwell describes the city, for example when he describes Victory Towers, which is an ironic name because the apartment building where Winston lives is described as run down, dingy, and falling apart. The room above the antique shop where Winston and Julia meet is described as very run down and full of antique items like a bed with a mattress. Winston feels like everything is always a little bit dingy and covered in dirt. Everything is like this, even the air, except for O'Brien's apartment (and everyone else in the Inner Party) which is in pristine condition.
As with the setting there are several places that give details about each character. Winston is 39 and has a varicose ulcer in his leg. He is skinny and looks older than he is. He smokes, he drinks, he commits thought crime. Julia is young and supple. She has naturally reddish looking lips, she wears a red Junior Anti-Sex League sash that accentuates her waist. She has dark hair and she too commits all sorts of crimes against the Party. Parsons, Winston's neighbor reeks of sweat and always wears athletic apparel. O'Brien is intelligent looking. He wears spectacles which he resettles on his nose often and Winston believes it makes him look rather safe to talk to.