Mages

Here is Bilbo's suggestions

Gear Stats
You will want these stats on your random gear stats;
 * 1) Matk
 * 2) Intellect
 * 3) Pdef
 * 4) Health
 * 5) Mdef/ Endurance

Astrals
You will want in the highest color
 * 1) Matk
 * 2) Health
 * 3) Pdef/Mdef,
 * 4) Disables crit damage, increased damage
 * 5) Charisma

Gems
You need to focus first of all on your Matk i cannot stress it enough, MATK MATK MATK, then comes your hp and Pdef, and if you have room you can throw some Mdef around as well, but those are the only gems you NEED, all others are a waste on a mage, trust me.
 * 1) Matk
 * 2) Health
 * 3) Pdef
 * 4) Mdef

Guild Skills
You will want to get gold as high as you can go first off, then you will want to go for in this order int, i got my int up to 6 before anything else, then, def/hp, you should keep them pretty equal as they are equally important, and then you can pickup the power/charisma, if you desire the little extra pdef from power, or the extra troops from the charisma.
 * 1) Gold
 * 2) Intellect
 * 3) Def/Health
 * 4) Charisma/Power

Skill Setup
There is lots of controversy, over which build is the best, and by far, the hybrid setup, is what has worked out best for myself, i know Angelbird also uses it, but it focuses mai nly on the support side of mage skills, for mp dungeons of high caliber, and team arena, but it also has the capabilities of dealing some pretty nasty damage.

Passives
You will want 2/2 Heart Elemental, 2/3 Mana Master, 2/2 Healing Empowerment, 2/2 Castinator

Usable Skills
Lightning Bolt 1/5, Rain of Fire 1/5, Delphic Thunder Frenzy 1/3, Thunderer 2/4, Restoration 3/3, Suntoria 2/3, Blessed Light 1/2, Meteoric Destroyer 2/4, Purification 1/3 This is the skill setup i use, i dont use Delphic Thunder Frenzy at all, this is also for level 44 mages, but, for level 40's id suggest Restoration 2/3 and Suntoria 1/3, untill you can get to 44, Feel free to tweak my skill setup in the game how you see fit, but this works out amazingly for me, i reach 1% on every world boss.