Post by Mahso
Mages wear cloth armor with Intellect, Stamina, Spell Haste, Critical Strike, Hit, and Spell Power (only on weapons).
Strength, Agility, Spirit, Block, Parry, Dodge, and Defense aren't needed.
As to your damage, one of the better ways to figure out how much damage you're doing is to get the
Recount mod. It not only tells you how much damage you do but detailed information on each spell you use, how many crits you had, and much more.
I wouldn't fret too much about doing the least amount of damage, especially before you get all of your spells and if the other damage dealers in the party are wearing heirlooms and you're not.
Maybe if you told us what specialization you picked and what you're doing in dungeons, folks can give you some specific tips to help your dps be the best it can be.
Welcome to World of Warcraft!