Here's a link to the "sig" templates:
1 column is 14 picas (2.375 in)
So if you're going for a half-column sig, it will be 7 picas across
It will ultimately be 300 dpi
Black must be 100% K
Dot gain is 30%, so it needs to be lighter than you think.
Subheads should be in Myriad Pro.
Here are the hex color values for the "Core Themes":