Mac OS X 10.6: Time Machine preferences
You can set up Time Machine to automatically back up all your important files, including your documents, music, photos, applications, and any other items you keep on your hard disk.
Use Time Machine preferences to select a backup disk, turn Time Machine on or off, and set options.
On and Off switch
Time Machine backs up your files every hour. To stop automatic backups, slide the switch to Off. Automatic backups will resume when you turn Time Machine back on.
Select Backup Disk or Change Disk
Click to select a disk or partition where Time Machine will store your backups.
To exclude items from being backed up, click Options. This button is visible only after you’ve selected a backup disk.
Show Time Machine status in the menu bar
To add a Time Machine menu to the menu bar along the top of your screen, select this checkbox. The Time Machine menu shows when your last backup was performed, and lets you begin a backup immediately or use Time Machine to restore files.