Add domains and domain aliases
On the Domain names page, you can add additional domain names to your Google Apps account. You can add them as separate domains or as domain aliases for your primary domain following these instructions.
Add email aliases
Every user has a primary email address, which is the email address created when the user's account was created and the address used to log into Google Apps. Google Apps enables to you create additional email aliases for a user. Follow these instructions on how to create email aliases.
Add user accounts
Before users can sign in and access a Google Apps account, they need a user account. You can add them using the Google Admin console following these instructions.
Delete user accounts
If a user leaves your organization, you might want to delete their Google Apps account. This destroys all the user's mail messages, and they'll no longer be able to sign in to Google Apps. Other data is purged within a matter of days. To delete user accounts follow these instructions.
Reset a users password
If a user forgets their password, or if you think their account's security might have been compromised, you can reset the user's password using these instructions.