Actually, it's the most used system of Horoscopic Astrology in the world (Chinese Astrology does not make use of a horoscopic chart). It adopted the horoscopic chart from Hellenistic Astrology, and much of its terminology and method is of Hellenistic origin, blended with systems native to India.
You will find many sites, if you do a search for Vedic Astrology, or Jyotish (its correct name. There are also many books of which Komilla Sutton's Essentials of Vedic Astrology is the most accessible. You will find a good selection of her books on Amazon, and if you have a kindle or a kindle app, you will find them at a good price reduction.
It's too big a topic to do an easy summary but you need to know (if you don't know already from your research) that it differs very much from the Astrology practiced by Modern Western Astrologers. It also uses a different zodiac, the Sidereal Zodiac which is more in line with the constellations than the Tropical Zodiac used in the West. Also it makes no use of the outer planets or asteroids and other bodies. It keeps to the classical seven that were used in the early Western Tradition.
