Since He is a child He is easily approachable, meaning the rules and regulations to his worship are not complicated. He likes sweets and so any function associated with Pillaiyaar is children's favorite. Amma makes a variety of sweets on that day. (But you have to wait until Appa completes the elaborate pooja [worship] ending with showing the food to God and prostrating before him.)

Though He is a child He is an ocean of knowledge and kindness and bestows blessings on his devotees. He is so wise and magnanimous that when Sage Vyasa wanted to compose the Great Epic poem called Mahabharatha (containing One Hundred Thousand verses) He requested Ganapathy for the favour of writing it down, as only Ganapathy could write the whole of it relentlessly at the same speed that Sage Vyasa composes the verses in his mind and dictates them. When they were engaged in this major task, the stylus which Ganapathy was using to carve on the palm leaves broke down. Not wanting to delay He breaks his tusk (elephants adore their tusks and take care of them very painstakingly) and starts writing down the verses.

Ganapathy is worshipped by devotees to alleviate trouble in any endeavor. A child going to school for the first day in its life, an executive attending an interview with a multinational or a father preparing his daughter's marriage prays to Ganapathy before beginning the same. As per puraanaas (Indian mythology) even other Gods pray to Ganapathy while going to fight a demon or seek a bride.
Even a saint praying to extricate himself from the transmigration of pre-birth and re-birth prays to Ganapathy for successful completion of prayers to his personal God (Ishta Devatha) the God most appealing to his mind by the force of his nature through his previous births.