Collection of Free Icons:
Galerie 1
Galerie 2
Galerie 3
Galerie 4
Galerie 5
Galerie 6

Context Menu uses the regular menu icon assigned by Joomla Admin Interface.
 
Menu Icons (Gif, jpg and png) should be located under "<Joomla_Root>/images/stories", you can upload your images using FTP or Joomla Media manager (recommended)
 

• To assign icons to your menu items, login to your Joomla Admin back end. 
• From the Upper menu select "Menu->mainmenu" 
• Click on the Menu Item (Click on Home for example)
• On the Right pane Select your menu icon "Menu Image"
• Click on Save.

 
Now you can Try your menu.
 
NB: Context Menu is triggered on Mouse Right Click only (Try right click to dispaly CM)