How do you set the scale for a specific project? For my current project, I've decided to use metric units. I am trying to work at the millimeter level, but when I create a new object (Cube) it's set to a one meter scale by default. How do I tell Blender that I want the default scale for all new objects in this blend file to be set to, for instance, one centimeter?

When using the Blender units scale I didn't concern myself with this stuff, but I'm trying to be more accurate in my designs.
You can set units and scale in the Properties Panel



Newly added cube after scaling to .01m with Edge Info Length enabled:



There are also a few settings in 3D-Views Properties-Panel (N) these influence only the display:



See also:


How to model effectively using exact measurements?
How can I use imperial units when entering measurements?