Knowledge of astrology has found to be nearly 82% accuarate which is higher than the 75% accuracy of present day medical science. people do not believe it. Just the way we have quacks, we have false astrologers who bring bad name to our science.
When you go to a Doctor, he asks you for symptoms, then asks you to get a few checks done to find what exactly is wrong with you and after that he prescribes medicines. But in astrology, people want the astrologer to straight away give out his predictions. It does not work that way even in astrology.
If a person comes to an astrologer, he will be asked his date of birth, time of birth and place of birth. After that the Kundali will be prepared. Based on the Kundali, a few questions will be asked to see the way the various aspects and planets have behaved for a person. But some very specific events will shine thru in the Kundali. Like my two ejections from fighters are very clearly given in my Kundali including the dates. They are reflected as near death experience resulting from accidents. But an astrologer will not know that the accident was from an aircraft. he will know that my life was under threat and where all I will recieve the injuries.
He will know the panch tatva to which my profession will belong to. Like my tenth house is Aquarious, an air sign which governed by Saturn which also is responsible for technology, computers, analysis as a lawyer, as a spy and also as an oil business. If aspected by bad planets, it can also make a person become dalal of women or become a person who deals in commissions.
I will suggest that you start by reading Bhrigu Samhita followed by Parashari. That will give you a lot of correct information provided you are able to remember everything.