“The son of Shiva and Parvati, Ganesha has an elephantine countenance with a curved trunk and big ears and a huge pot-bellied body of a human being. He is the Lord of success and destroyer of evils and obstacles. He is also worshipped as the god of education, knowledge, wisdom and wealth. In fact, Ganesha is one of the five prime Hindu deities (Brahma, Vishnu, Shiva and Durga being the other four) whose idolatry is glorified as the panchayatana puja.
Ganesha’s head symbolizes the Atman or the soul, which is the ultimate supreme reality of human existence and his human body signifies Maya or the earthly existence of human beings. The elephant head denotes wisdom and its trunk represents Om, the sound symbol of cosmic reality. In his upper right hand, Ganesha holds a goad, which helps him propel mankind forward on the eternal path and remove obstacles from the way. The noose in Ganesha’s left hand is a gentle implement to capture all difficulties.
The broken tusk that Ganesha holds like a pen in his lower right hand is a symbol of sacrifice, which he broke for writing the Mahabharata. The rosary in his other hand suggests that the pursuit of knowledge should be continuous. The laddu (sweet) he holds in his trunk indicates that one must discover the sweetness of the Atman. His fan-like ears convey that he is all ears to our petition. The snake that runs round his waist represents energy in all forms. And he is humble enough to ride the lowest of creatures, a mouse.”
~ Courtesy of http://hinduism.about.com/od/lordganesha/a/ganesha.htm