How to Attach Stylesheet to Template (was: Newbie times 6, linking)?

I've managed to get the site just about to the point of uploading a test version, but before I do that I want to eliminate the css info in the pages themselves and link them to an external style sheet. I left it in the pages because there were a number of times that I needed to modify it before the whole set of child pages were complete. I'm prertty sure that it's not likely to change significantly from now.

I've saved out the css for each of my template pages. I am assuming that once I delet the <style> infor from the template and link it to the seperate css file in the css folder that when I save it it will update all the child pages. Is this correct?

So the main issue is; *how* do I link it. What is the proper format for doing that? I'm assuming that the link to the css file goes where the <style> info is now, but how much of a path do I need to specify? The template files, after all, are probably not going to be uploaded to the site, either for testing or when it goes public. Just the child pages, and the folder with the various css files.