[oldwolf]

maps.google.com might help

go to satellite view. you'll be able to find railroad tracks and depending on how current the pictures are, possibly some old buildings or industrial areas. just be careful around the old buildings though.

it will at least give you an idea of where to go to look so you don't wander aimlessly. always scout out the areas before you send a client there. makes it look more professional.

you can also look on your town's chamber of commerce page to see if they have pictures of buildings that you can scout out for cool backgrounds. (i.e. brick buildings, old signs, etc.)

finding good locations is a matter of investing time to go out and look. it's tedious at first but pays off in the long run.

now if it comes down to what makes an interesting background then look at other people's examples on the web. not everyone has the same tastes but you'll get an idea of what you like and what you don't like.