Choose the arrow tool from the toolbar. Select the notes you want to beam by dragging the mouse over them. Do this by clicking and holding down the left mouse button and moving the mouse until you have encompassed all the symbols, and then releasing the mouse button. The selected notes are highlighted in reverse video and an edit menu appears. Select Beam from the edit menu. Choose one of the durations from the submenu, and then either Beam Up or Beam Down from the next submenu.
If you want more than one duration for your beamed grouping (for example a dotted eighth beamed with a sixteenth), choose Complex for the duration and then Beam Up or Beam Down from the next submenu. Now for each note in your group, select the duration for that note from the dialog that appears. The Skip Note option in this dialog gives you the opportunity to leave selected notes within the group unbeamed.
If you are beaming a single note head, a stem and flags are added to your note head according to the duration and direction you specified from the beaming submenus.