Planets in Astrology

The planets of the zodiac consist of Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, the Sun, and the Moon.  Typically, the planets become a more important part of your horoscope when applied to your whole birth chart (or star chart), as each person has many pieces to put together with the Houses, Planets, Aspects, etc.  Planets are very important for each individual because they are constantly changing in arrangement; the exact position of the planets at the moment of your birth is different than every other person alive today.

The planet which affects you most is the one related to your sun sign (however, if your Moon sign is in Cancer, you are affected by the moon more than the planet of your sun sign, unless your sun sign is Leo)  Below is a list of each astrological sign, the planet it is ruled by, and how that affects it:
Aries:  Mars (god of war, conflict, and masculinity) - prone to aggression and competition
Taurus:  Venus (goddess of love, beauty, the arts, and femininity) - tend to be creative and love beautiful/luxurious things
Gemini:  Mercury (messenger god and ruler of communication) - tend to enjoy travel and have cleverness, but may also be nervous
Cancer:  Moon (rules emotions and intuition) - prone to moodiness
Leo:  Sun (symbolizes authority and power) - tend to take on leadership and enjoy being the center of attention
Virgo:  Mercury (messenger god and ruler of communication) - tend to be reasonable, but also nervous
Libra:  Venus (goddess of love, beauty, the arts, and femininity) - tend to be self-absorbed and love luxury
Scorpio:  Pluto (god of the underworld/dead) - tend to be unyielding and emotional
Sagittarius:  Jupiter (ruler of the heavens and god of fortune) - tend to enjoy fun and to pursue selfish goals
Capricorn:  Saturn (god of farming/money) - tend to be self-disciplined and responsible
Aquarius:  Uranus (god of the sky) - tend to be innovative and unconventional
Pisces:  Neptune (god of the sea) - tend to seem mysteriously glamorous and to be deceptive

Part of the reason why I put so much faith in astrology is because it recognizes that each person is individual.  Every moment, the planets shift alignment in some way, making a new chart with new characteristics.  Astrology is a great way to begin to understand individuals and to learn how to interact more successfully with others.