Sorry for the question but a basic quick start seems to be lacking. After installing I was logged into the admin section but now I have no idea how to.
Is there a way to log into it? There is no visible link.

<path to your install>/admin. There is no visible link unless you enabled the user-login-out plugin. Normal visitors do not need to see such a link generally.

This example assumes that you installed Zenphoto in a directory called [i]zenphoto[/i]

Login to the admin pages:

With mod_rewrite:
www.yoursite.org/zenphoto/admin

Without mod_rewrite:
www.yoursite.org/zenphoto/zp-core/admin.php

That's great thanks. I still think you need a quick start guide.

You are welcome to provide one!