You can add as many timers as you need to the window by clicking "Add" in the toolbar. Before you add a timer, choose the sort of timer you need (but you can change it later too). Each timer shows a little triangle in its upper left corner, indicating its mode (up, down or clock). Each timer in the interface (represented by a small square with a LED interface and buttons) finds its counterpart in the list at the bottom of the window.
To start a timer, press the start button on a timer; to pause or stop it, press that same button again. To reset it, press the left button (with the double-arrow). To configure a timer, either left-click the LED-display or right-click and choose "Configure" from the context menu. The timer has to be in resetted state to be configurable. For more configure options, click the little "..." button in the lower right corner of the timer (only visible when you first clicked the LED-display or chose "Configure").
A count-up-timer does not need to be configured, it just counts upwards (to a maximum of 100 days). For a count-down timer you have to set a time to count down from (the default is 1 minute). For an alarm-clock, you need to set the alarm time (default is the next full hour and the current date). You can set other alarm options in the alarm clock settings ("Configure...").
To remove a timer, just click the little "X" button on the corresponding timer. You can also use the context menu of the list, to operate the timers. You can also use the global settings (menu: Settings), which should be self-explaining.
You can switch to a miniatur mode, to save screen space. Click the "Resize" button in the toolbar to toggle the size. This mode is especially useful, if you are using a lot of timers at the same time. In the miniatur mode, the display does not feature the sub-display for additional information. All other functions remain the same.