Users & Groups Preferences on Your MacBook
Each user on your system has an entry in the list on your MacBook's Users & Groups pane. The panes and settings here change, depending on the access level of the selected account.
The settings on the Users & Groups pane can include
Password pane: Click in these text fields to enter or edit the account name, password, and password hint for the selected user.
Click the Address Book Card Open button to edit the card that you mark in the Address Book as My Card. Mac OS X launches the Address Book, and you can edit your card to your heart’s content.
You can change the corresponding Apple ID for each user account from this pane as well. If you’re sharing your Mac with a number of other users, each person can set up his or her own Apple ID account!
If you have administrator access, you can enable Parental Controls for the selected user account or open the Parental Controls pane.
Picture well: From the Picture well — the square area to the right of the Account list — you can choose one of the thumbnail images provided by Apple to represent you, or drag a photo in from iPhoto. Click the well to display the thumbnails. Click Edit Picture to drag a new image from the Finder or take a video snapshot using your Mac’s iSight camera.
Login Items pane: The applications and documents that you add to this list launch automatically each time that the current user logs in to Mac OS X.
To add an application or document, click the Add button (which carries a plus sign), navigate to the desired item and select it, and then click the Add button. (Alternatively, you can simply drag an item from a Finder window into the Login Items list.)
To remove an application from the list, click to select it and then click the Remove button (which has a minus sign). Each application can be launched in a hidden state — its window doesn’t appear on the Desktop. To toggle an item as hidden or visible, enable the Hide check box next to the desired application.
The order that Login Items are launched can be changed by dragging entries in the list into the desired sequence.
Note that a user must be logged in to view and change the items on the Login Items pane — even an Administrator-level user can’t access another user account’s Login items!
You can even set up Login Items directly from the Dock! Right-click the desired Dock icon to display the Options pop-up menu and then click Open at Login.
Login Options pane: Look for the button with the little house icon at the lower left. Click it to set a number of global options that control how users log in.
For example, you can choose to display either a Name and Password field on the Login screen (which means that the user must actually type in the correct username) or a list of users, from which a person can select a user ID. (If security is a consideration, use the Name and Password option.)
You can also add VoiceOver spoken interface support at the Login screen, making it easier for physically challenged users to log in to this Mac.
If you choose, you can log in automatically as the selected user by clicking the Automatically Login <Username> pop-up menu and choosing your account. (Definitely not a secure feature — especially for MacBook owners — but convenient as all get-out.)
The Login Options pane also allows you to enable or disable Fast User Switching, and you can prevent anyone from restarting or shutting down the Mac from the Login screen by disabling the Show the Sleep, Restart, and Shut Down Buttons check box.