The default install of Ubuntu includes the Gnome desktop environment and the Nautilus file manager, this is the Linux equivalent to Windows Explorer or Mac OS X’s Finder. In Ubuntu and Linux in general most programs hold their settings and configuration data under a folder prefixed with a . (period) in your home folder. By default most file managers hide these folders to make using the system and finding/accessing your files easier. For this reason it’s best just show hidden files briefly and not all the time.
To show hidden folders in Ubuntu simple open a Nautilus window (your home folder) and press Ctrl H. This will show all hidden folders in and files in this window where ever you navigate to. If you would ike to rehide them simply press Ctrl H again.
Here are screen shots of Ubuntu with hidden files both shown and hidden: