Healer's Guild. They use magic to heal people. Trying to heal a mortal injury could kill the healer if he/she tries to heal the person alone. Not everyone can afford their rates, and they are expensive. You could make these guys the halflings.
Elementalist Guild. Sub-sections in this guild could include earth, fire, wind, water, ice, and lightning. Elementalist Barbarian Orcs?
Artisan's Guild. They make magic weapons and armor. Maybe they also make magi-tech airships and magi-tech trains. They could have a monopoly on these forms of transportation. They could be dwarves. Very stereotypical, I know.
Druid's Guild. Talking to animals and/or the beasts you're talking about. Controlling plants and weather. Some healing powers and artisan like magic as well. They can pretty much harness/influence every element except for fire. Elves be here.
Adventurer's Guild. Consists mainly of non-magic users. Sub-sections could include Warriors and thieves. Predominantly humans.
In this world, metal CANT be infused with magic, but a magical sword made of wood or stone can be just as sharp if not sharper than a metal sword. Regardless of any magic, a well forged metal sword will always be more durable than a wooden or stone sword, however. Holding or wearing metal inhibits/weakens a magic users powers considerably. It would just be plain stupid for a magic user to wear or wield anything metal that was larger than a dagger. It would be like going from a gigantic flamethrower to a candle flame. If you put a magic user in a suit of metal armor, they won't be able to use their magic.
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As for beasts... You can never go wrong with dragons, dire-animals (this includes dire-dinosaurs), and elemental creatures of colossal proportions.
