What are the Vedas?
The philosophy and religion of the Hare Krishnas are based on the Vedas, or the Vedic literatures, that were written in Sanskrit (ancient Indian) 5000 years ago. The Vedic literature comprises the four Vedas (Rig Veda, Sama Veda, Yajur Veda, and Atharva Veda), the Upanisads, Puranas, Ramayana, Vedanta Sutra, Mahabharata, and others. Furthermore there are a great number of additional texts, addressing any and all aspects of life, like Ayurveda (knowledge of health and medicine) and Jyotirveda (Veda of astrology).
The most prominent of these books for Hare Krishnas is Bhagavad-gita, which is an exerpt from the Mahabharata, and Srimad-Bhagavatam, the most preeminent Purana. Besides these, some books from the time of Caitanya Mahaprabhu around the 1500’s are very popular, such as Caitanya Caritamrita and Bhakti Rasamrita Sindhu. Srila Prabhupada translated these and other Vedic texts to English with extensive purports, so they are available and understandable for a modern western audience.