I'm a long time lurker who has decided to finally start posting. currently wondering what books to get for more fluff and background for the shadowrun universe, i just started playing a couple of months ago.

There are oodles of books out there, what are you really looking for background on?

Welcome to the shadows chummer.
You might want to take a look at this link.
I hope to have been usefull.

Thanks Allthenothing, that link is very helpful, I am really just trying to get a sense of the world, I know nothing about Shadowrun other than the little bits of fluff in the core books.

depending on where you live:
Shadows of North America or Shadows of Europe are both pretty good. Or Shadows of Asia

SoTA 2063 and SoTA 2064 , Sprawl Survival Guide are also very good.

IF you can find them the damn near perfect books are the original first ed Seattle Source book back from like 1990 and Neo-anarchists Guide to Real life.

I think I understand you, I had the same problem.
What I can say is that getting a hold of all the books is a quite pain in the @$$ but it's (mostly) worth it.
By the way, CGL should relise (I don't know when, but it's under development) a book named 6th World's Almanac or something like that; if I got it right it should be an SR history book, something for those new to SR that might want to know more about the story but don't want to go insane trying to hunt down books that have been out of print for who knows how much time.

I can't speak for the original Seattle sourcebook but those titles are indeed great, they give important info about the plot and, most importantly, add many tiny bit of info about everyday life that allow the settings to come to life.
For plot related sourcebooks I may point Bug City, Portfolio of a Dragon - Dunkelzahn's Secrets, Year of the Comet and System Failure; they cover some among the biggest shake-ups the SR history had gone trought.
I also suggest to aquire (if possible) the whole "Target: ...." series, CyberPirates, Corporate Download (it's under development a new corp book, thought) and Dragons of the 6th World.
Oh yeah, easily obtainable, there is the first 4th ed. plot/fluff sourcebook: Emergence.

I took the original Seattle source book with me when I went to Seattle last spring.

The reason because I can't talk of that book is that I don't have it so I'm totaly ignorant about it.
I wasn't disagreeding with you.

The 1st ed Seattle source book was one of those things that FASA did way back when. It was very much a blow by blow of each of the major regions of seattle and their subdivisions. All told it was the most detailed of the Sourcebooks for any one city (including the expansions on seattle put out later). I am looking forward to the update to the seattle, and hopw it goes into similar detail.

Back to the OP, of the 4th ed sourcebooks, probably your best bet is Runner Havens and Corporate Enclaves. Both give you background on different styles of play and locations to run them in.

On that note, has anyone done runs in Japan?

Oh yeah the Seattle Sopurcebook rocked. Still use mine a lot. The maps were the main focus of my gaming group - everyone likes to know where they are running, but with a quick access to Google Maps you too can see the lay of the land. Mainly it was chock full of location descriptions and runner/decker commentary and written in the style of a public datanet download/tourist guide that got "ammended." some cool adverts are laced throughout and my favourite is still the full colour one for the Big Rhino.

As for other background books, it depends on where you're running and whethe you're a player who wants more details on the Sixth World or a GM who needs more realistic information to write up a scenario. Echo the use of Shadows of North America, Europe & Asia series from 3rd Edition. A lot of ground covered therein if not as detailed as the earlier stuff. Neo-Anarchist's Guide to North America is a goldmine for pre BBB/CCZ days and the NEo-Anarchist's Guide to Real Life has some great lifestyle fluff and atmospheric articles.

Regarding Japan though - no, not yet at least.