Artemis is a super sexy tomboy virgin goddess. Being a virgin, for her, means being at that stage in life when you are most attractive to eligible bachelors and yet still titillatingly off limits. She was a complete Daddy's girl and, endowed with the precociosity of all the gods, sat on Zeus' knee not long after her birth and demanded of him a long list of things including his word to never force her into marriage. Unlike Athena, she is very committed to her mother Leto and her defense helps gain Artemis the name "Arrow-pouring." She may have spent her time running through the woods like the hunter she was, but she still stepped up to defend herself and other Olympians against giants. Artemis was a strong protectress of young women and even young men, but expected perfection from her followers and her punishment for those who didn't meet her expectations was often death.
Artemis (as well as her twin brother, Apollo) was the daughter of the goddess Leto and Zeus. Interesting note, they got it on in quail form. Now, Hera wasn't too happy about her hubby, Zeus, messing around on her like that, and sent all sorts of horrible things after Leto (like a Gadfly and a scary dragon/serpent named Python. She also made a decree that Leto could not be allowed to rest anywhere on solid ground. Poor Leto eventually made it to Ortygia, where Artemis was born. Artemis was a really good daughter, because when she was born, she saw her mother in pain, and helped Leto over to the straits between Ortygia and Delos. There, between an olive-tree and a date palm (the two sacred trees of Leto as the Egyptian and Palestinian Lat), Artemis played midwife as her brother Apollo was born. They say that until Apollo's birth, Delos had been a floating island, but as the baby boy was spilled upon its sand, the island grew roots and had been fixed since. But even there, Hera forbid Eileithyia, the Goddess of Childbirth, to come to her. Eventually, the gods bribed Hera with a beautiful necklace, and Eilithyia went to Leto. Some stories say that Artemis, the first born, was a relatively easy birth, but her brother definitely wasn't. And so immediatly after she was born, Artemis became her mother's midwife and after like nine hours, brought her brother into the world. So, since then, Artemis has been considered a Protectress of Childbirth.
There are other versions of the birth (there always are). The one above is most widely accepted, but there are other things too. Some say that Apollo was born underground. Homer says he was born in Lycia. The Ephesians say he was born on Ortygia (near Ephesus), and two other random countries claim him as their native son as well. He is much loved, is Apollo. Artemis has more reference in the myth above. Originally (pre-Hellenic myth), Artemis was an orgiastic goddess - and as that, the quail was her sacred bird. The island of Ortygia (Quail Island) was the resting place of flocks of quails as they migrated north in the spring.
Artemis was a self-made goddess. As a child, she crawled into Daddy Zeus' lap and asked him to support her in her plan to be a huntress goddess and live in the mountains. She asked for sixty nine-year-old (remember? maidenhood!) Oceanides in her retinue, twenty nymphs from the river Amnisos. She didn't care about towns, but she got 'em anyway. She also reiterated her earlier commitment to assisting women giving birth. Next stop? Bow and arrows! She got the Cyclops to make them for her, and they were silver and spectacular and they made her the counterpart of her archer brother. She didn't stop there, though. She went on to Pan, a forest-y type god, and he gave her hounds for her hunting activities. Self-made goddess all the way.
Even though Artemis had sweet and loving beginnings, and indeed, she could love most intensely, she could also be very cold and unforgiving. This is a very god-like trait that every god and goddess (barring Hestia) has, at some point, displayed. One well-known story of her chilly personality has to do with the hunter Actaeon. This story, by the way, has a longer and better written version in the Myth Pages. But I digress. So Artemis had just had a long day of hunting, and was sweaty and gross, and ready for a nice bath. This was deep in the woods in a sacred pool, and it wasn't very likely that anyone would come upon her. But people of Actaeon's family had a history of bad luck, and he did just that. Now, every man knows that if you see a naked goddess (unless it is Aphrodite, or she invites you to see her naked) you run away, and PRAY that she doesn't notice. But either Actaeon wasn't very bright or he was so enraptured by her beauty that he didn't move. What he did was stare. Bad idea. Artemis heard him, turned around, and in fury threw water at him. As the thre droplets hit him, he was transformed into a stag. At that, Artemis whistled for his hounds, and they ripped their unfortunate master apart.
Artemis and her brother were passionate. And one person they both loved dearly, beyond each other (for their bond was almost comletely unbreakable), was their mother Leto. The twins loved and defended their mother with a passion unparalleled, and woe to the god or mortal who offended her. One such woman was named Niobe. Now, I have little pity for Niobe, because she was just stupid. She had the gall to complain loudly that people paid too much respect to Leto. She cried that Leto had only two children, where she had seven boys and seven girls. Hmmmm. Not for long, smartgirl. Once the twins heard they came to her house and Apollo shot everyone of the boys with his golden arrows of extreme pain. Artemis shot the girls with her painless silver arrows, and they all lay down on their beds and died. Some stories say that the youngest girl, Chloris, was spared, but it is unclear why. Niobe wept uncontrollably, and I think some kind god turned her into a rock.
Like most goddesses, Artemis was not a happy camper when she was insulted. It is a generally good rule to follow, that one should not insult the gods by calling them names or even by comparing oneself to their beauty, skill, or anything else. The same rule applies with most nymphs. One idiot, for example, named Chione, bore the penalty for daring to compare herself to Artemis. She asked Apollo to tell her she was more beautiful than the goddess. This he would not do (smart man), but Artemis found out, and shot Chione. She also killed Ethemea for not sacrificing to her. Another example was when some dude forgot to sacrifice to her and she sent the Calydonian Boar to ravage everything. A girl named Gerana was turned into a crane for talking smack.
There are two versions of this story, but the more well-known, and generally accepted version, is pretty grim. It has to do with Iphigenia. We have already clarified, I believe, DON'T PISS OFF A GODDESS, and Iphigenia's daddy, Agamemnon (see him in such blockbusters as The Iliad, or incorrectly but amusingly portrayed in Troy), blatantly ignored this most important of rules, and upon expert shooting of a deer, declared that even Artemis couldn't do it better! Bad move. Also, Iphigenia's grandad had welched on a sacrifice he was supposed to make (disrespect all thru this family!), so that didn't help matters. Anyway, time passes, and the Trojan War is about to start led by our own Agamemnon. So he starts off and then the poop hits the fan. The sea goes crazy (depending who's telling the story, there's no wind, or it's an insane hurricane) and it becomes quite clear that Artemis is making answer to their leader. Agamemnon is forced to sacrifice Iphigenia, more or less, and sends her off (telling her she's gonna marry hunky Achilles) to die. Now see, that seems highly problematic to me, because ain't this goddess supposed to be protecting dewy virgins? The Greeks were divided on this. Some say she died believing to the last she was gonna marry Achilles. Some say that Artemis turned her into Hecate. And some say that at the very last second, Artemis substituted the girl's body with a deer's and Iphigenia went off to become a minor goddess. Really, it's hard to tell, but it's easy to see that Artemis had a lot of different perceptions, and was no wilting flower.
In addition to being a strong goddess in her own right, with all the foibles that accompany that, Artemis was also the leader of a band of wood nymphs (Draiads). These nymphs, like Artemis, were sworn to chastity and stuff. So when they got raped, or chose to mess around, there were some pretty serious consequences. One story is that of Callisto. Callisto had the misfortune to be raped by Zeus, and Hera turned her into a bear that Artemis promptly shot. There are a few questions about whether or not Artemis knew who she shot, but most people think she knew. Or at least I think so. There are other nymphs and women who suffered similar fates, but I will not go into them.
I will not tell the whole story of Orion here, since there are many myths connected to him. Instead I will only discuss his relationship with Artemis. In my favorite version, Artemis starts really digging hanging out with Orion 'cuz he's like super-hunter dude. Now, Orion was sleeping with Eos - who was known for digging on guys already - and Apollo got worried about the chastity of his sister, and started worrying that Artemis would be as taken in as Eos. That doesn't really appear to be the case, but Apollo was jealous, so he went and arranged with Gaia to send this crazy big scorpion after him. Now, some say that this animal was just too much for Orion and killed him (and that Artemis was pissed for a while, but relented when Apollo helped her hang Orion in the sky). Another version says that Orion ran away from the scorpion - or rather, swam away to Eos' island, hoping that the Goddess of Dawn would protect him. But then Apollo told his sister that the figure bobbing in the sea was a villain who had just seduced one of her priestesses. Then he challenged her to hit the bobbing object. She did, and killed her friend unknowingly. She tried to get Asclepius to revive him, but Zeus destroyed him before he got the chance. And so ended Artemis' only romance before it could begin.
The myths above come mostly out of Classical mythology, and they reflect the society in which they were written - but if you're trying to really understand the depth of this goddess, you need to look a little further. As mentioned above, although the Classical stories peg her as Apollo's twin (where she tends to pale in comparison), she wasn't always a sibling. Like lots of other gods and goddesses (tho not Apollo, actually), Artemis seems to come from goddesses in a lot of different Mediterranean and eastern cultures, and she wasn't always as sweet as she appears for the Greeks. In some of her cults she was an orgiastic goddess, and in a few she required human sacrifice. Sound familiar? (See Iphigenia's story if you can't quite recall.)
Great! Now you know the Classical stories. Really, it's the only story people bother to tell anymore. However, it's not the only story that exists. In fact, even though Artemis seems pretty overshadowed by her brilliant brother, there was a time when they weren't even considered siblings. Apollo has always been a Greek God, but Artemis was a Goddess who came from a lot of different cultures. For instance, earlier myths place her as the daughter of Dionysus and Isis or of Zeus and Persephone. It was a while before people started making her Apollo's twin, but once they did, her power seems to pale a bit.
She has a ton of epithets - the best collection I've seen online (291!!) is over at GoddessADay.com, and if you're interested you should go check it out.