Have you ever wondered where Mac OS X 10.5 (Leopard) stores essential files, such as Mail's mailboxes or Safari's bookmarks? Most of these files are stored somewhere in your Home folder. To locate the files, first open the Users folder and then your Home folder (the folder with your user name). Next, look in these specific folders:
Now that you know where all those essential files are located, it's easy to back them up with a backup program or with an Automator workflow. Note that these locations apply also to Mac OS X 10.4 (Tiger).