Edward Blake's apartment was never completely or clearly shown, but it appears several times since the beginning of the first chapter, when Detectives Joe Bourquin and Steven Fine were investigating Blake's murder. Also, in the same chapter, when Rorschach climbs up the building to investigate himself (also in the cut scenes from his murder), and in the second chapter while we see flashbacks and the scenes from Blake's murder.
The reader of the graphic novel is never told what floor Blake lives on, however, the height is sufficient enough for Blake to have been killed when thrown out of his picture window.
In the film we pretty much see Blake's apartment as in the comic, just some parts of it while the Detectives are investigating it, and when Rorschach climbs to investigate himself.
While in the comic we never get to see what exactly happens in the murder of Edward Blake, in the movie they choose to use it as a scene prior the intro, in which they give a version of what happened when Adrian Veidt broke in to kill him, showing that Blake did put in a fight, as suggested by one of the detectives, and probably contradicting what we get to see in the novel, in which we only see scenes of him getting beaten up.