Lord Ganesha - God of Wisdom
"Pratham Tula Vandito Ganraya ! Pratham Tula Vandito" you might be wondering because starting words are from our regional language Marathi meaning "Before of all Gods I am worshiping you and bowing before you".
This is common tradition in India, every good dead of life, new business enterprises is started with remembrance and worship of Lord Ganesha. Most commonalty pronounce Shlok [Chant] of Ganesha pooja is "Vakratunda Mahakaya - Suryakoti-sama-prabha - Nirvighnam kuru me deva - Sarva-karyeshu sarvada".
According to Hindu religious books Ganesha is Manas Putara [Spiritual son] of Goddess Paravati, wife of God Shiva. Hindu Puranas says that Ganesha was brought to life by Goddess Paravati, she created him from outer dusty layers of her body in absence of Shiva and assigned him duty of safe guarding entrance of her residence so she can take bath without disturbance. While Paravati was taking bath Lord Shiva return home and was denied entrance by Ganesha. Both Shiva and Ganesha were not aware of each other's relation with Goddess, hence in anger Lord Shiva used his Trishul and cut the head of Ganesha. Afterward to please Paravati, Shiva brought Ganesha back to life but with elephant head. Paravati looking at her beloved son asked about the insult that might other can do, due to elephant headed body. Lord Shiva at that moment blessed Ganesha with boon that he always will be worshiped ahead of all Gods.
Lord Ganesha is most worshiped deity of India and even in many other countries of the world. Maharashtra is famous for Ganshoutsav, during the British rule, Bal Gangadhar Tilak has started the tradition of public celebration of this religious festival and since that time Maharashtra, specially cities like Pune, Mumbai and Kolhapur become famous for this.
Lord Ganesha is treated as the God of education & wisdom, there is story about the wisdom of Lord Ganesha, once Ganesha and his big brother Kartikay were in race for completing seven rounds of the world. Kartikay was confident of winning this race as his vehicle is Peacock and of Ganesha is Rat. Kartikay set off for the journey where as Ganesha was staying there only, he got up, made seven Pradashinas (moved around) of Lord Shiva and Goddess Paravati, this shows the wisdom of Ganesha, as for the children world starts and ends around his parents.

Ganesh Idol
Idol of lord Ganesha are generally created from the earth, which indicates relation of God and life. In common idol form this Elephant headed God have four hands
Right Hand [1]: holding Parsha expressing divines powers
Right Hand [2]: is the one stretched with blessings and boons, insuring devotee for remaining away from all types fears, agony and hurdles. (often worshiped as Vighanharata)
Left Hand [1]: Holds "Ankush" a common device used to control moments of gigantic animals like elephants, symbolising powers of removing ignorance and anguish. (often worshiped as Dukh harta)
Left Hand [2]: holds modaks - favorite sweet dish of lord - indicating that God brings the favorite things and joy in the life of devotee. (often worshiped as Sukh Karata)