Almost all have been categorized on the wiki: http://www.uesp.net/wiki/Skyrim:Easter_Eggs
Reference to what exactly in the rather large collection of works by Edgar Allan Poe. I myself noticed once a reference to him to, but I'm unable to remember what it was. It wasn't Ranmir, I think.
I don't get most of these references anyways :c
Like that Troll slaying book...I'm a fan of Finntroll, but the only thing I see is the author called Finn, and it's about troll slaying.
I don't see any "what could be" referrences towards their music(besides the title).
I see references this way, though:
"During combat, Brynjolf may exclaim "So it's to the pain then!" This is a reference to Westley's famous threat to Prince Humperdinck in The Princess Bride."
But what if it isn't? It's just a sentence.
Unfortunately, I never heard about Edgar Allen Poe. I will look him up later today.
Edit: typo
Edit: Woops, just discovered a kind of double post! Sorry.
E-gads, what are they teaching in school now? ( joking)
I miss alot of the Easter Eggs myself.
Funny - the Star Wars section of the wki doesn't include the line 'we're here to rescue you,' which comes up in the game every now and then.
I'm not an expert on Poe's life, but I don't remember him having a lover named Isabel. His much younger wife Virginia died after a long period of illness some time after he wrote The Raven, maybe she's the one you're thinking about? The Raven certainly doesn't mention any Isabel, but I guess it might have been inspired by a real person/event.
Anyway, I don't see how Poe having a love affair gone wrong could become an Easter egg. This kind of unfortunate event happens to everyone at least one time in their life.
http://www.eapoe.org/works/poems/fairyle.htm, references an "Isabel".
Bard's leap summit, also why does the entrance of that area look like it is in the shape of the letter A?