Scenario is as follows: admin adds users (coordinators). Coordinators should be able to add another type of users (editors) which can create content. What is the best solution to this scenario? I don't want any of the users assign roles to other users. Coordinator should be able to add only one, defined type of user.
There's a module for that: Administer Users by Role.
This module allows site builders to set up fine-grained permissions for allowing users to edit and delete other users — more specific than Drupal Core's all-or-nothing 'administer users' permission. It also provides and enforces a 'create users' permission.
To use this module:
- Create a role for the users who you'd like to be able to create/edit/delete other users
- Give that new role the 'administer users' permission and give it the desired Administer Users by Role permissions
I'm using it exactly for the same purpose you described.