How do I configure the Block Access module?
This module is an administrative level module. You can use it to configure who can create/administer/view/etc blocks. For instance, what I did to realize what the module does, logged in as admin:


Install and enable the module Block Access
Create a new role, lets say testadmin, and grant to it every permission
Create a new user, lets say testuser, with that role
Log in with user testuser and create a dummy block
Log in again as admin
Edit the permissions of the role testadmin and deselect the permissions "Administer block access settings" and "Create blocks", under the section "Block Access" (these permissions are added by the Block Access module)
Log in again as testuser and try to create another dummy block
End of the exercise, because now the user testuser can't create blocks...


In this exercise I only used two permissions, but the module Block Access implements a lot more!