You may Look at Astrology classes held at Bhartiya Vidhya Bhavan. If you are not getting any institue you can even pick up some books written by B.V. Raman and read those. Some of the great books for beginners are
1. Astrology For beginners.
2. How to Judge a Horoscope Volume 1 and Volume 2.
One of my Favourite Book by an American Vedic Astrologer David Frawley is Astrology of the Seers.