My group's settled on Shadowrun for our first game (we'll be using the 4th Edition Anniversary rules), and I'm looking for general recommendations and advice.

Our first session will be to run through a oneshot with pregenerated characters to get a feel for the rules and ambiance. Can anyone recommend an available mission? Ideally the run would be short (being new to the mechanics will slow us down quite a bit), touch on a wide variety of rules aspects, and have a nice gritty feel to it. I'm leaning towards doling out the Street Samurai, Bounty Hunter, and Combat Mage from the Catalyst Quick-Start Rules to my three players.

In more general terms, can anyone recommend specific GM resources? Are there any can't live without helper programs to make play run smoothly? Any particularly broken rules that need a patch? Advice on group composition to that everyone in the three player team can share the limelight?

Based on a bit of SR 2E experience long ago, I'm strongly inclined to make Matrix related stuff the domain of NPCs unless a player is very interested in playing a decker. Am I short-changing our fun if I do this?

Thanks for any advice or thoughts.