I'm about to run my first game of Shadowrun, 4th Edition. I've played 3rd, 2nd, editions (maybe first, I Can't remember), in the past. Are there any DM tools out there that people consider useful, or perhaps tips and things to watch out for from others that have run 4th ed Shadorun?
I'm looking at running some variation on "On the Run", the published adventure by the company, to start with. I have four players, none of whom have played Shadowrun before, although all experienced gamers.