If you open a Finder window you will notice that it has a Toolbar and a Sidebar. The Toolbar contains certain buttons that will allow you to accomplish tasks or activities such as get more information, eject a disk or delete a file. The Sidebar, on the other hand will show you locations. Ideally, the Sidebar is there so that you will have convenient access to locations that you use most often.
The Finder Sidebar has a default setup and the locations are arranged by type: devices such as computers and hard drives, shared folders and networks, your home and applications folder and at the bottom. You can show as much or as little as you want. To customize your Sidebar, open your Finder Preferences and select the Sidebar tab. It will give you an option box where you can check or uncheck which items you will be able to see on your Sidebar.
An item on the Finder sidebar is simply like the alias on your desktop. It won’t contain the files so adding or removing them from the Sidebar will just remove the shortcut but the not the files. To add, organize and remove folders and other items on the Sidebar, the click and drag method is still the most effective. Drag folders from the main windows of your Finder onto the Sidebar to add them. You can rearrange the order they appear by dragging the item up or down. To remove items from the Sidebar simply drag them until they disappear with a cloud of smoke.
This way you can easily customize the Finder Sidebar.