Upanishads are one of the most ancient scriptures of the world. It is said that the Upanishads are an expression of the ultimate reality of existence. The orally transmitted knowledge of the reality of man, life and existence is the subject matter of the Upanishads.
It is said that the Upanishads are not authored. There is no source and beginning for the Upanishads except for the antiquity of time through which it has been passed down. Upanishads are a great read to explore the mysteries of life.
There are various commentaries and translations of the Upanishads. Any of them could serve as a good beginning. The Upanishads are unimaginably insightful and deep. Each layer of Upanishads reveal a much deeper dimension of truth and knowledge. It is a must read for an inquisitive mind.