To backup your data you can simply select "Backup|Backup Reminders Now" menu item.
After you select it a dialog will show up asking you to select a folder where you would like to save the backup file. The filename will contain the date so you will always know which file is backup for which date. For example - a backup file could be called "TalkingReminder-12-31-2005.backup"
TIP: Copy your backup files regularly to a CD or DVD drive or simply on another coputer, hard drive or USB drive to avoid single point of failure. If your hard drive with Talking Reminder on it carashes - you will always have a backup copy to restore from.