Standard link for user to create site/blog on a network?

Where would a user on a network normally go to create a site/blog? What is that link in a standard multisite installation?

I have a heavily customized multisite installation that “forces” every user who signs up to also register one blog.

But older users, from before I made the chances to the site, don’t have blogs, so I need to provide them a link to a registration form.

If you have a clean standard multisite installation, please let me know what that link looks like.