Back up to avoid a Data Loss Event.
66 percent of internet users have suffered from serious data loss.
Here are the ways I recommend to back up your Mac.
If your Macintosh is running System 10.5 or 10.6, a great backup system is built in.You need a second hard drive as big or bigger than the one in your Mac. That's it. Configuration is easy. Time Machine is constantly backing up your Mac. I have restored data from a Time Machine backup several times and it has worked perfectly. If you have Time Machine on your Mac, I recommend you use it. Time Machine is one of the many great benefits of being a Mac user.
Use SuperDuper or Carbon Copy Cloner
If your Macintosh is running System 10.4 or earlier, I recommend either of these programs. These programs make a complete copy of your hard drive to another hard drive. You need a drive as big as or bigger than your Mac’s hard drive. If you use Time Machine you can also use either of these programs to make a second backup. Two backups are better than one.
Backup just your User folder.
Your data is in your User folder (or it should be). If you back up your User folder, you have saved your data on your computer. If your User folder is less than 16 GB, one way you can do this is using a Flash Drive. You can also back up your User folder to another hard drive or to a server if you are connected to one. Music and photos can make your User folder quite large.
I recommend buying backup hard drives from Other World Computing. I also recommend having more than one backup.