The Greek Gods
The major deities ruled from atop of Mount Olympus in northern Greece. Zeus, king of the gods, preferred this area because it proved to be a visual vantage point to observe the actions of mortals. Originally there were twelve gods, but the addition of Dionysus forced the complacent goddess Hestia to give up her seat. Hades also is an important deity, but he resided primarily in his realm of the underworld. Below is a brief description of the gods and their functions.
Aphrodite
Aphrodite's name has a strange, almost perverse origin. After Cronos, father of the gods, castrated his own father Uranus, he tossed the genitals into the sea. From the foam—aphros—arose a goddess of such beauty the gods were immediately drawn to her.
The poet Homer, however, claims she has much simplier origins: she is the child of Zeus and Dione, an ancient sky goddess. Homer gives her a husband, the ugly Hephaestus. But she is much more attracted to the fair and handsome Ares.
Aphrodite, as the goddess of love and beauty, would naturally have many amorous exploits; aside from her adventures with Ares, her romance with the mortal Adonis is infamous. She also loved the mortal Anchises and thus was the mother of Aeneas, the founder of Rome. She is therefore regarded as a direct ancestor of the Romans.
Aphrodite's city was Cypress, her place of birth. Her animals were the swan, sparrow, and dove, and her plants included the myrtle, rose, and poppy.
Apollo
The devine archer, Apollo is said to represent the male ideal of beauty: youthful, muscular, perfect. He and his twin sister Artemis were the children of Zeus and Leto, a Titan. One of his first acts as a god was to kill the giant serpent Python of Delphi, which thus became his city.
Apollo was the god of medicine, prophesy, and music. He had many loves, both male and female. The most famous is Daphne, the nymph who fled from him and was transformed into a laurel tree. The laurel became sacred to him, and he is often depicted with a crown of laurels around his head. His shrine in Delphi was saught after for the power of his oracle, or prophetess. He is considered a "true" Greek god; so much so, that the Romans had no counterpart, and eventually adapted his name and character for their godhead.
Ares
Ares was the son of Zeus and Hera, and yes, even his own parents hated him. Zeus even declares such in the Iliad. Of course, Zeus had his own favorite and I believe he does Ares a gross injustice by playing such favorites. Perhaps Ares would not have been as violent as he was if one of his parents would have actually acknowledged his existence other than their disdain for him. Some claim there were no cities where he was worshipped, which is incorrect: Thebes honored him as the father of Harmonia, wife of its founder Cadmus, and in Thrace and Sparta he was particularly popular.
Ares was a young, handsome god. Older representations depict him as a bearded warrior, but around the Fourth Century BCE he gets a youthful, clean-shaven— one that looks more like Apollo as a soldier. As a beautiful god, he naturally had many loves: Aphrodite, Eos (Dawn), and—as the Roman god Mars and father of Romulus and Remus, builders of Rome—Rhea Silvia. He had many children, including Phobos (Fear), Deimos (Pain), and Eros by Aphrodite. After his daughter Alcippe was raped by Poseidon's son Halirhothius, Ares killed the violator. On the hills of Athens, Ares was put on trial—the first murder trial ever. The hill where he was acquitted is known as the Areopagus, or "hill of Ares".
Artemis
Artemis was the Mistress of Beasts and all things wild. She was the twin sister of Apollo and the daughter of Zeus and Leto, a Titaness. A virgin tomboy, all animals were sacred to her, but the bear and boar were especially significant to her.
Aside from a huntress, Artemis has many representations, one of which is a protectress of child-bearing women. The famous statue of Artemis of Ephesus portrays her as a multiple-breasted mother figure; indeed, her origins did derive from the Great Mother goddess. Her latter-day depiction as the Virgin Huntress came later.
Artemis was not, as many believe, associated with the moon. Her Roman counterpart Diana is often described as the moon, but the Greeks had a separate goddess, Selene, as the lunar representation.
Athena
The Greeks adored her. They even named a city after her: Athens. She won the city from Poseidon by granting Greece with the simple gift of an olive tree. Athena was THE Greek goddess. She represented wisdom, courage, and protection for many heroes such as Heracles and Perseus. Like Artemis and Hestia, she was a virgin with the plain sort of beauty which being a goddess afforded her, yet she somehow had the audacity to believe it was she who deserved the golden apple marked "for the fairest". Her animal was the owl and her plant the olive tree.
Her birth is a curious story. Athena is often regarded as the daughter of Zeus only. Her mother was, in fact, Metis (counsel). Zeus learned that any child Metis bore could possibly usurp the father so when he discovered her pregnant he swallowed her. Later, he had a painful migraine; Hephaestus struck his head with a hammer and Athena, fully armed and grown, sprang from his head. Since Zeus proclaimed that he alone fathered the child, she quickly became his favorite. If Athena is your "favorite", then don't bother to continue to browse through my pages. I don't particularly appreciate egotistical suck-ups, which is precisely what this brat was.
Demeter
The goddess of agriculture and fertility, Demeter was the sister of Zeus and, with Zeus, the mother of Persephone (or Kore). Any agricultural animal was dear to her, and corn and wheat were her main plants. Her most famous story involves her daughter's abduction by Hades and her quest to save her.
Hades wished to marry Persephone, and one day kidnapped her. Demeter, frantic, wandered the entire earth calling for her daughter. While she did, she neglected her duty as goddess of agriculture, and the harvest became none. She finally consulted Helios, the sun god, who had witnessed the abduction. She went to retrieve Persephone, but had discovered her daughter had eaten pomegranate seeds, which meant she would have to stay in the underworld with Hades. A compromise was finally met where Persephone would stay with her new husband four months a year--each month for each seed she had consumed. During those months, the earth turned cold and bitter: Demeter's sadness for losing her daughter.
Dionysus
Dionysus was the late entry into Olympus. He was the son of Zeus and the mortal woman Semele. The mere fact that Semele was mortal caused quite an uproar; many of the other gods delcared they would not let Dionysus be seated because of his mortal heritage. Hestia, to keep the peace, quietly and peacefully surrendered her seat in order to accommodate the new god.
Dionysus was the god of the vine and his followers, called maenads, or "mad women", traveled the woods in a frenzied, almost drunken state. Euripides's brilliant play The Bacchae narrates how refusing to follow the godhead of Dionysus—whatever his mortal ancestory—can be fatal.
Hades
Hades was the god of the underworld, a place he drew after Zeus, Poseidon, and he divided up the kingdoms after the gods defeated the Titans. He is often depicted as a middle-aged, bearded god who closely resembles his brother Zeus.
Apart from his abduction of his wife Persephone, Hades really has little mythology. His name means "the unseen" and that is precisely how the Greek viewed—or didn't view—him. He was not seen as an anti-Christ or Satan, nor was his kingdom regarded as a "hell". The Underworld was a place for both saints and sinners, and Hades basically was the innkeeper.
Hephaestus
After Zeus had given birth to his daughter Athena, Hera decided she could do the same. The product of her effort was the devine artificer of the gods, Hephaestus.
Hephaestus, though talented, was an ugly god, and lame also. He was, however, married to the most beautiful of goddesses, Aphrodite after he demanded it when he bound his mother in a golden chair. She was not faithful, and Hephaestus even caught her in bed with her favorite lover, Ares, the god of war.
Hera
Hera, wife of the father of gods Zeus, is often portrayed as a quarrelsome and bitter goddess, and for good reason. She had to constantly keep her husband's libido in check!
As queen of the gods, she did demand respect (her name means "lady"). Her origins, like many of the major goddesses', probably lie with the Great Mother myths before the paternal gods became en vogue. Hera guards marriage laws with an iron fist, and her anger when her husband violates these laws is so absolutely frightening that Zeus hesitates sometimes. With Zeus, she is the mother of Ares, Hebe (cupbearer of the gods), and Eileithyia (a goddess of childbirth).
Zeus had tricked Hera into marrying him by disguising himself as a cuckoo so it was sacred to her, along with the peacock in honor of Argus the Hundred-Eyed whom was killed while under her direction. Argos, the city, was her patron town.
Hermes
Hermes was the son of the Zeus and Maia (daughter of the Titan Atlas). A clever young god, he soon wandered from the cave from where he was born and killed some of his brother Apollo's cows, inventing strings for a lyre. He wore his shoes backwards in order to confuse the angry Apollo, who nonetheless discovered it was his new brother who was responsible for the death of his herd. Zeus, however, was amused by the young trickster, and quickly the new god earned his place in Olympus.
Hermes became the messenger god, though he was probably originally a pastoral god. He had a reputation for being sly and playful and could easily outwit the best. Appropriately, he was the father of Pan.
Hestia
Very little is known about this serene, peaceful goddess other than she was the sister of Zeus and both Poseidon and Apollo sought her hand in marriage. She knew their lustful demeanors and vowed to remain a virgin.
Her primary habitat was the home as she was the goddess of the hearth. Her Roman counterpart, Vesta, was highly honored by Vestal virgins and secret ceremonies, but Hestia remains a mystery. She was, however, invoked before all sacrifices.
Poseidon
Poseidon drew the sea as his lot when the gods were dividing kingdoms. This suited him just fine, and he quickly took the reigns of his realm. He married the Nereid (sea goddess) Amphitrite by sending an ambassador, Delphinus, to ask her hand. She accepted, and Poseidon put Delphinus's image in the stars (the Dolphin).
The images of Poseidon resemble those of Zeus, and his manner is close to his brother's also. He could not resist a beautiful female (or male). His lust led to the fateful house of Pelops, and also the myth of Theseus.
Poseidon was strangely associated with horses, and with Demeter produced the awesome mare Arion, and with Medusa the mystical winged-stallion Pegasus. The dolphin was obviously another favorite.
Zeus
Zeus, as you have probably already guessed, was the father of the gods. he received this title by defeating his father Cronus, a Titan, and castrating him. This led to the battle with the Titans for control of the earth and heavens, with Zeus and his siblings and children eventually winning.
Zeus was married to his sister Hera but his roving eye made him the consort of many other goddesses and mortal women (and men). Apollo, Artemis, Hermes, Dionysus, and Persephone are a few of the children he had by other women. His tendency to favor his bastard sons and daughters over his legitimate ones is apparent, especially in Homer.
As king of gods, it was natural his bird was the elegant eagle, and his plant the solid, sturdy oak. The mighty thunderbolt, crafted by Hephaestus and the Cyclops, was his weapon.