Resources
There are plenty of useful external resources for Shadowrun. Some of the most useful ones are listed here:
This is an amazing list of SR podcasts to found around the interweb. I strongly recommend the Arcology podcast, their actual play is awesome.
Awesome map of all the locations from the 2072 source book.
Great map of 6th world, but done in google maps
This is your starting point for all things Shadowrun. Detailed rules questions and debates, as well as setting queries can all be answered, or at least discussed here. If there's one thing I've learnt about Shadowrun, is that there is no definite rules interpretation.
An excellent, although somewhat dated collection of pages outlining the setting, in the main. This resource should be kept up to date - we should all pitch in to keep this site current, as our one version of the truth.
This is an application for generating characters, and it is invaluable. Trying to create player characters (or NPCs for that matter) is gruelling hard work, without this application. It is free, and open source, and written in C# - what more do you want?
This site combines an online Shadowrun magazine (3 issues), a list of Shadowrun-esque news articles from RL, and a forum. The news articles are about a year out of date, which suggests that the site is no longer being updated, however there are some good articles in the magazines.