The importance of Lord Ganesh is mentioned in many Puranas and Vedas. Rig Veda, Yajur Veda, Sama Veda & Atharva Veda have the reference of Ganapathi. Upanishads have given great importance for Ganesha Puja. There are two exclusive Upanishads dedicated to Vinayaka – 1. Ganesha Atharvashirsha Upanishad, 2. Ganeshathapi Upanishad. Vallabha Upanishad describes the significance of various names of Ganesha.
The term ‘Ganadhipathi’ occurs twice in the Rig Veda. It is not clearly mentioned about Lord Ganesha.
In Padma Purana, the importance of worshipping Lord Ganesha before any puja or Yagna is mentioned. It explains why Ganesha is the first god invoked in all Hindu pujas & rituals.
As per Shiva Purana, to calm down Lord Narasimha Swamy after killing Hiranyakashapu; short Ganesha appeared with huge belly riding a small mouse.
A part of Brahma vaivarta Purana describes the meaning of GA & NA. It also tells the mahima of worshipping Ganesha in uplifting spiritual and moral energies.
We have a special story in Brahma Purana on how Ganesha has got the name ‘Lambodhara’
Mudgala Purana tells how god Ganesha became the Lord of Arishadvarga & how Ganpati upasana is helpful for human beings in getting triumph over the destructive qualities.
In ‘Shanti Mayukha’ the magnitude of first puja to Ganesha is explained.
‘Sri Tathwanidhi’ explains the 32 forms of Ganesha. It has special mention for Simha Ganapathi.
Another Scripture called ‘Rupa Mandanam’ has all the information about Ganesha Panchayatana Puja.