Q:

How far should you break up stylesheets? 

I'm building a new site for my company, and I'm at the stage where I've created the html mockup of the first page.  I'm going to use this as a basis for the rest of the site.  I'm thinking of organising my stylesheet better now I've got the design looking consistent cross-browser, but I'm wondering how far to go when I'm breaking it up. 
One idea is to have the following:

reset.css
typography.css
layout.css
colors.css

but where do I draw the line?  theoretically I could go on and break them down into classes, ids etc, but I think thats going overboard. 
Does this seem a reasonable method? 

A:

Coincidentally, A List Apart had an article covering this today.  They recommend separating out into a few main categories, including some you listed (type, layout, color), but going further to include various tricks to keep older browsers happy. 
On the other hand, keeping everything in one css file keeps the requests between browser & server down.  A compromise might be to keep things separate for development, and merging for production (as a part of your build process, naturally :p). 

A:

I don't tend to split typography into a seperate stylesheet, although it seems like a good idea.  I'd keep colours with typography though.  My typical way is to have the following structure:
base.css

Global style used throughout the site
Aims to be extendable, for example so that it can be reskinned (but using the exisiting layout) for a microsite. 
Implements/imports reset.css

page.css

Implements any page-specific changes. 

microsite_skin.css

See base.css point 2

