[Zope] Security questions

[Garito]

Hi
I have some kind of problems to understand how Zope's security rules

If I have these distribution:

root
    Blogs
       Blog1
       Blog2
       Blog3

where
Blogs: Folder
Blog1, 2, 3: Coreblog product

How can I configure the security to have 3 users (User1, User2, User3) 
who can log on ZMI to manage their weblogs?

I suppose (but don't work properly for me) I need to create a user 
folder on Blogs folder and create 3 users on it, isn't it?

Thanks!