if you are just looking for adventure ideas, here are where I start looking:
Newspaper. No shit, you can find a metric tonne of story ideas just from story headlines that you can then play with an adapt to an SR mission idea.
Youtube. Do a random search on you tube for "Crime Story" and you'll get 10,000 responses covering everything from fiction to history, all of which can be played with for a SR mission.
As for location... I generally place the players in an area with the most published info on it, just so everyone has the same level playing field for info on the setting, as opposed to just "winging it"... but then again, I play with a pretty traveled group, so...