Mages smell of burnt hairs. Now while this a possibly true in Jareths case.. It is not true of all mages..
The mage Guild is Based purely.. on Magic.. All the powers/abilities/skills are based on the mages ability to cast spells. A mages fighting style is based entirely on not taking any damage what-so-ever. This is because mages have no healing abilities other than that of potions/items. The mage makes up for this in regening sp extremely quickly.
- Create Golem- Summons a golem to tank for smaller level mages or just provide extra damage. (Note: This power can be used on other players to give them a golem as well.)
Here is a pretty good example of a golem, 
Mage Types -
Summoners do exactly that, Summon monsters to do their bidding. (i.e tank/do damage/cause trouble) Summoners are generally tank better because the monster(s) do all the damage and tanking and the mage doesn't expend as much sp thus allowing more combat time. (Most summoners self tank past Glvl 110) The downside to this is that if your control of your summons exceeds your concentration threshold (85%-100%, depending on the Exaction skill), your summons can/will turn on you and attack you instead of the mob you were fighting. As mages cannot regen hp, this is usually fatal.
Evokers are the hardcore spellcasters, using sp to hurl fireballs, summon lightning strikes, and freeze their enemy to the bone. The evoker has some advantages and disadvantages to the summoner. 1> Evokers burn a ton of sp casting spells everyround thus reducing combat time; but the turn side of this is that generally, evokers do more damage than summoners as their damage types are elemental (flame,cold,electricity, etc) and since the mobs restistants are lower to the these types of damage, the spells do more damage. 2>Evokes dont summon monsters(generally speaking) so they have no chance of having their summons turn on them. The downside is that smaller level mage defensive spells arent really all that bs, meaning that since the mage doesnt have monsters tanking for him/her; their spells are the only thing protecting them. And those spells, arent that great.
Mages have a multitude of spells which do many useful, weird, and random things.
Identify- This spell converts SP into identified items. 55sp/cast(Guild Level 19).
Planewalk- This spell opens a small area where 2 players can 'meet'. Since you must exit the way you entered and no items can be exchanged this spell is used to provide/get boosts for/from other players.
Fools Gold- Allows you to create enourmous amounts of fake money. Very amusing to drop, then go invisible and watch some happless player try to pick the coins up.
Invisibility-If you dont know what this does, see your doctor immediatly.
Phantom Sentry-Allows you to summon a ghost to watch a room for you.
Haste-Can be cast on yourself or summons, allows 2x attacks a round.
Stinking Cloud(fire ball, etc)- Area attacks that allow the you to attack all mobs in a room. (this is not a good idea for small mages, since your golem can only tank one mob at a time)
And many more, over 100 actually.
Anyway, thats my two sense; anyone who knows more about this topic, please fill free to edit away. -Maximus