Perhaps no other religion has as much ancient original literature as Hinduism does. To start with, the most fundamental and ancient scripture is the Veda. Veda means knowledge. God himself taught this knowledge to Brahma, the creator, who imparted it to the Rishis. Vedic knowledge is divine knowledge.and is very vast and comprehensive. The Vedas discuss God, religion, science, mathematics, logic, grammar and many other subjects. The great sage Vyasa organized this knowledge in to four Vedas - Rig Veda, Yajur Veda, Sama Veda and Atharvana Veda. This knowledge was learned by disciples from a Guru through oral tradition. Hence the Vedas are also called Shruti. The word Shruti is derived from the root shrun which means to hear.
The Hindus believe that the Vedas contain ALL the knowledge of the God’s Creation. The last chapters of the Vedas are called Vedanta (end of the Vedas) and are collected in the Upanishads. Here is the discussion of the nature of Brahman, the God, extracted from the vast literature of the Vedas. There are one hundred and eight significant Upanishads.
The next tier of the scriptures are called the Puranas. Purana literally means the ancient. Some believe that the Puranas are even more ancient than the Vedas but this is doubtful. There are eighteen Puranas in all each describing the life story of God in a particular incarnation at a particular time and space. The Puranas are works of great literary beauty and present the intricate philosophies of Veda in a format that is easy to understand and remember. These are extremely popular literature of India. There is not a single Hindu who does not know at least a few stories from one of these eighteen Puranas. The Bhagavata Purana is the most popular of the eighteen and is a monumental work containing twelve books, called Skandas. This Purana narrates all the ten significant incarnations of God although the main emphasis is on the story of Krishna and His miracles.
Next come the Itihasas - histories. The Ramayana and the Maha Bharata are the two principal epics of India. The Ramayana is the biography of the Lord in His incarnation as Rama, the prince of Ayodhya, an ancient dynasty in Northern India. The Maha Bharata contains eighteen chapters and more than 200,000 lines of poetry (100,000 couplets). It is about seven times the size of Iliad and Odyssey combined. Although this is mostly a historical narration, it is interspersed with discussions of God, dharma, ethics, duty, good, evil and almost everything under the Sun. Therefore it is sometimes called the Fifth Veda. It is in this work that the greatest of Hindu religious texts, The Bhagavad Gita, is embedded. The Bhagavad Gita is narrated by the Lord Krishna Himself to His friend and disciple Arjuna on the battlefield of Kurukshetra.
The Bhagavad Gita contains eighteen chapters and discusses the nature of God, Creation, destiny of man, man’s relation to God and means of realizing God in one’s life time. This work presents in a distilled form the very essence of a universal religion.
In addition, there are also dozens of works written over the centuries by scholars, saints and gurus which explain and expound the meaning of the Vedas and Upanishads. This vast literature is called the Bhashya literature. Of course mention should also be made of the huge literature that was written by saints and other God realized persons who passed on to us the experiences of their personal spiritual quest.