Astrology is one of the oldest types of divination. When used properly, it can be quite revealing and useful. However, it should be stressed that many sites, magazines and books which claim to have the answers, don't. Most horoscopes are comlpete hogwash written by a journalist with no real astological talent. That's why they're for entertainment only! A good astrologist will incorporate many other things other than your sun sign.
Houses
For more information see Marlene's Niche. There is a large section directed to teaching astrology as well as links to free astrology software.