The Panel
The default panel holds a few Plasmoids: starting from the left, there's the Kickoff application launcher. You can use it to start applications, open recently opened files and the usual logout/shutdown options. There's also a structure that allows you to browse through your applications. The layout has been optimized for the use case that is most common: starting an application. The default tab is the Favorites tab that holds the most-used entries. In the beginning, you'll probably find yourself using the Applications tab more often. Once you have found out what your most frequently started applications are, click on the items and select the to add them to your Favorites (or directly into the panel or on the desktop. Note that you need to "unlock" Plasma by means of clicking on the desktop for any kind of modification). If you prefer KDE's traditional menu-style application launcher, change it by clicking on the menu button and selecting .
The next icon (looking like either a desktop computer or a laptop, depending on the type of machine) is the Device Notifier. Plug in a USB disk and a dialog will open that allows you to open the device in Dolphin.
The next item on your panel is the Pager. It allows you to switch between your virtual desktops. If you change the layout of the Pager through the option, which will also affect the layout and animations that are shown in KWin's effect -- (Switch on desktop effect, press Ctrl+F8 to see it.) For larger pagers, selecting typically makes sense.
The taskbar is up next on the panel. It shows an area for all open windows on all desktops by default. You can make it show all open windows on the current desktop only by checking when you right click on the task manager, between two windows. The size of the text on the taskbar items can be set in System Settings under the ->->. Right-clicking on the taskbar brings the Settings dialog where you can choose several options to customize your taskbar.
Next on our default panel is the System Tray, which is used by traditional applications as a dock. Right clicking on the System Tray allows you to hide or show icons.
The right-most Plasmoid in the default panel holds the Digital Clock. This clock can display the time in different timezones as well as have its size changed. The clock will adjust its font size to the area it is given by the surrounding containment (that is the panel in this case). If you choose to display the date, this date will be rendered using the option from the System Settings Font dialog. The time will take the rest of the space. So in the end, you'll choose yourself the amount of information displayed, and if that fits. If you want to display more information, make the panel larger or put the clock on the desktop where it can grow freely.
