Mac OS X 10.6: Creating and modifying user accounts
Use Accounts preferences to set up and manage accounts for users, decide what types of privileges and access the user will have, and determine how users will log in to the computer.
If you have an administrator name and password, you can use Accounts preferences to add, delete, or modify accounts.
Creating new accounts
Use Accounts preferences to create new user accounts. It’s recommended that you create a unique account for each person who uses your computer, so they will have access to their own home folder and documents.
Changing login options
You can change the way users log in to the computer, modify the login window, enable fast user switching, and more in the Login Options pane.
Opening items automatically when you log in
If you always use certain applications or documents, you can have them open automatically whenever you log in by adding them to the list in the Login Items pane.
Changing your account password
You can change your password, or if you have an administrator name and password, you can manage the passwords of other users.