The default Dock is powerful, but it gets even more useful when you include the items in it that you use often and organize the Dock to suit your preferences. You can move icons around the Dock, add more applications to it, remove applications that are currently on it, and add your own folders and documents to it so they are easily accessible.
You can change the location of any installed item on the Dock by dragging it. When you move one icon between two others, they slide apart to make room for the icon you are moving. However, you can't move most icons across the dividing line; for example, you can't move an application icon to the right side of the Dock.
You can't move most icons across the dividing line on the dock; however, exceptions to this are dockling icons, which can be placed on either side of the line.
If you move the icon of an open application that isn't installed on the Dock, that icon moves to the location to which you drag it and becomes installed on the Dock.
The Dock has two icons you can't move at all: Finder and Trash/Eject. The Finder icon always appears on the left end of the Dock, and the Trash is always on the right end. Other than these two end points, you can change all the other icons on the Dock as much as you like.
You can add applications, folders, and files to the Dock so it contains the items you want. Drag the item you want to add down to the Dock and drop it where you want it to be installed. Application icons must be placed on the left side of the dividing line, and all others (folders and files) are placed on the right side (the exception is docklings, which can be placed on either side). Just as when you move icons on the Dock, when you add items between other icons already installed on it, the other icons slide apart to make room for them. When you add an item to the Dock, an alias to that item is created and you see its icon on the Dock.
You can add multiple items to the Dock at the same time by holding down the key while you select each item you want to add to the Dock and then drag them there.
You can remove an icon from the Dock by dragging it up onto the desktop. When you do this, the icon disappears in a puff of digital smoke and no longer appears on the Dock.
Because the icons on the Dock are aliases, removing them doesn't affect the applications or files that those aliases represent.
If you drag a minimized window from the Dock, it snaps back to the Dock when you release the mouse button. You remove minimized windows from the Dock by maximizing or closing them.
You can also add any folder to the Dock; when you click a folder icon on the Dock, the folder opens in a Finder window.
When you place a folder on the Dock, you can open its Dock menu that shows the contents of that folder (refer to Figure 5.4). All the subfolders also appear in hierarchical menus.
This feature is one of the most useful the Dock offers. You can use it to create custom menus containing anything on your Mac (literally). The uses for this feature are almost unlimited. Some ideas include the following:
Add your Home directory to the Dock so you can easily move to an item within it.
Add your project folders to the Dock so you can easily get to the files you need for the project on which you are working.
Add the Applications folder to the Dock. This gives you quick access to all the applications on your Mac that are installed in the default Applications folder.
Although adding folders to the Dock is useful, it can be easier and just as useful to add folders to the Places sidebar in Finder windows. The benefit to adding folders to the Dock is that you can access them without bringing the Finder to the front.
You might find that adding folders to the Dock is even more useful than adding application or file icons. Remember that you can make more room on the Dock by removing items from it. For example, you might choose to remove most or all of the application icons from the Dock and instead add the Applications folder to it. This works well, although you do lose the indicator features of an application's icon (such as Mail's new mail alert) if its icon is not installed on the Dock directly.