We all like decorated items than normal ones. Everyone like to add icon/image to their site's menu links but we need some tricks to add that into our drupal site's menu link. I am going to show you various methods to add an icon/image to the drupal menu links.
1. theme_menu_link() :
It would return html elements for the menu and it's submenu. We can change the menu html elements using this function and this function must be written in our theme's template.php file. In this example, I am going to add icons to the main menu.