Haven't really played with publishing sites too much but from what I'm reading - assuming you have sharepoint server and publishing has been activated then a new publishing site will use the nightandday master page and (out of the box) the main content will have some links to things like enable anon access and manage navigation.
I've now created 2 pub sites (one dev one prod) and on both servers the masterpage looked more like minimal rather than nightandday. There is no main content and the only branding appears along the top.
When I open the site in SPD 2010 and look in the master pages folder I see v4, minimal and default. No nightandday.
I go to site settings and go to master pages. I can select night and day from the master pages drop down... which I do.
Now the site shows the Adventure Works branding but still no main content.
On my home server creating a new publishing site that shows the adventure works branding and the content is a one step process - create site: publishing