Astrology is a very vast subject and no decision could be taken considering a single fact. Birth star is only one of the many factors (not the one and only factor mind it!)affecting one's destiny is analyzed as per astrological calculations. Again good and bad is to be understood is also to be understood in a broader prospective. It is based upon for which aspect you are looking at it. For eg. J Jayalalita's Birth star is Magha, now how can one decide it is good or bad for her? If you analyze the time of India's independence, 00.00 hrs 15th August, 1947 again the star would turn out be Magha, but that never mean that India is having only bad effects. Since you have mentioned that you have started reading astrological books, please go through them and learn more you will understand on your own how to analyze things. I can suggest you many good astrological magazines and books in case you are really interested.