If you're using a window or static resolution, what is the screen size you are designing for?
At the moment I'm working with a 4:3 window ratio for my game. The actual resolution doesn't matter since my UI elements will be designed to scale with different screen sizes.
How are you building your 3D world? What tools are you using?
So far I've used 3D Studio Max to create my entity geometry (guns, player character etc), and I've been using Google Stetch Up for my environment (I might change this to Max though). I've been considering writing a simple level editor for positioning my levels, but might simply end up doing this in the game engine itself.
What is the setting or theme of your game?
Robots fighting in city streets.