I'm following a drupal 5 tutorial that advises to get the Admin Role module. Is this module still useful for drupal 6?
Part of the drupal 6 installation is the creation of an admin account. What does Admin Role do? Does it work on that account and improve it somehow, or does it create an entirely different admin account?
It can still be useful in Drupal 6. Drupal has a user, the user created when you install Drupal that has all permissions.
This module creates a role which by default has all permissions. You can give users this role to give them permission to everything. It's especially useful when you are developing on fx a staging server and are adding a lot of modules. This way you don't need to configure permission to other developers every time you install a module.
The module is still useful - although I believe it's included as part of Drupal 7's core functionality.
What AdminRole does is create a role which will have all permissions added to it as modules are created. Users set up with this role then can do most of what the user 1 (admin) can do, but not everything. (For one, running the update.php requires user 1 and there's no permission that allows another user to run it.)
There's some benefits to setting up an admin role as opposed to handing out user 1 passwords to everyone. One is that as people do things on your site, their user name gets written to the watchdog - so it's easier to find who did something rather than seeing all changes credited to 'admin'. Another is that if you need to revoke or remove a few permissions from a user, it's easier to change which roles are on their account than to give them a new account and change the admin password and pass the new password around.
Really, the admin account should be locked up tightly and used rarely - better to have developers and users working in their own accounts and taking advantage of the permissions system than giving out the keys to the kingdom.