This looks like a good plugin. I am a little confused on how to use it though. It seems extremely complicated.

What I would like to do is create a user who can login to the admin panel but only edit a certain pre-created page. The person should be able to create subpage for that page. But that is all.

I have no idea how to do that after looking through the usage guide link. By chance could anyone give me some very simple instructions? using WP 2.7.1