Press the right mouse button and hold it down. A menu titled Application menu appears. Select an application (the preconfigured items might not be available on all systems, but an xterm should be, so move the pointer over the submenu xterm and select the item login shell by releasing the mouse button above the item).
The application's window will appear on the screen.
Move the pointer somewhere over the window's border and hold down the left mouse button. The famous ude honeycomb will appear. Move the mouse pointer over the hex-icon on the upper left and release the mouse button. Oops... The window just disappeared together with the hex menu. It has been minimized. Some people also call this state of a window iconified. There are no icons for such windows in UWM however. You might be wondering how to get this damn window back then if it cannot be accessed through an icon. Well, the answer is simple: through a menu!
Press the middle mouse button and hold it down. (Yes, you'll need a three-button-mouse if you want to use UWM properly. However to get a first touch perhaps your X-server's emulate3buttons will do it). A menu called Windows menu appears and either shows a list of workspaces which will pop out submenus if the pointer moves over them or (in case there is only one workspace) represents the only workspace's submenu itself. The submenus are a list of the windows on the corresponding workspace. Search the only submenu with an entry (which is your program's window of course) and select this entry. The window will deiconify and reappear on the screen.
Now move the pointer somewhere over the window's border again and hold down the middle mouse button. Move the mouse and see what happens: The window is being dragged around. Release the window by releasing the mouse button.
Try out resizing the window using the right mouse button on the window's border.
To finally close the window select the central upper button in the window's hex-menu.
Start another xterm and a second one so that you finally have two windows on the screen now. Move them around to be overlaping. Now press and release the middle mouse button somewhere on the upper window's border without moving the pointer. The window will be lowered under the other one. Reraise the window by pressing the left mouse button and releasing it again somewhere on the border without moving the mouse. (The hex menu will appear as long as the button is pressed - ignore it.)
Now try around with uwm's keyboard focus handling: Move the mouse over one of the windows. Its border will change its color. The window now has keyboard focus, try it out by typing something. Also type something into the other window.
Close both windows, the first one by typing exit into it, the other one by using the honeycomb's close button.