Where can I find the files I want to back up?
Deciding which files to back up, and locating them, is the most difficult step when attempting to perform a backup. Listed below are the most common locations of important files and settings that you may want to back up.
Personal files (documents, music, photos and videos)
These are usually stored in your home folder (/home/your_name). They could be in subfolders such as Desktop, Documents, Pictures, Music and Videos.
If your backup medium has sufficient space (if it's an external hard disk, for example), consider backing up the entire Home folder. You can find out how much disk space your Home folder takes up by using the Disk Usage Analyzer.
Any file or folder name that starts with a period (.) is hidden by default. To view hidden files, click View ▸ Show Hidden Files or press Ctrl+H. You can copy these to a backup location like any other file.
Personal settings (desktop preferences, themes, and software settings)
Most applications store their settings in hidden folders inside your Home folder (see above for information on hidden files).
Most of your application settings will be stored in the hidden folders .config, .gconf, .gnome2, and .local in your Home folder.
Settings for important parts of the system aren't stored in your Home folder. There are a number of locations that they could be stored, but most are stored in the /etc folder. In general, you won't need to back up these files on a home computer. If you are running a server, however, you should back up the files for the services that it is running.