Mage - Frost

Purpose

Survivability and Control, supplement raid wide spell crit % through Winter's Chill. Big AoE damage for fast trash clearing. Frostnova, Improved Blizzard, Water Elemental Freeze to keep the enemies in place.

Talents

Key Talents are Elemental Precision, Frostbite, Winter's Chill, Shatter, Icy Veins, all the +dmg to Frost and crit, reduced cooldowns to all frost spells, Summon Water Elemental, Brain Freeze, Fingers of Frost, Frost Channelling

I supplement my frost build with 11 in arcane, for Clearcasting and Focus Magic, but the dps gain is minor and with full raid buffs, mana is never an issue anyway. You could go all 71 in frost and still see decent dps.

Ability Rotation

Frostbolt, then Frostbolt, followed by Frostbolt. During most fights, you will never want to move off of Frostbolt; the ElitistJerks forums have demonstrated pretty conclusively that anything else is a drop in DPS and DPM, because Ice Lance simply doesn't do enough damage to be worth chewing up a cooldown on, and a frost mage doesn't have the talents to make the Fireball do enough damage to make up for the lost casting time on another Frostbolt. During trash, or when the boss is down to 1% health, however, watching for and using Fingers of Frost procs for Ice Lances and Brainfreeze procs to more rapidly burn down the mob can be useful. Sometimes burst damage is good!

Key Cooldowns

Icy Veins. This is tricky to master to maximize dps, but an easy way is simply to use it anytime its up and Cold Snap near the end of boss fights to get more damage in before the enrage. If you have a trinket that boosts spellpower, use it just before you pop Icy Veins to maximize the effect.

Water Elemental. The elemental's dps scales with your spellpower, so use him anytime your spellpower is boosted through a trinket/proc. Cold Snap to get him back into the fight when you can. Similar tactics for Mirror Image.

There are lots of advanced mechanics to think of once you get down the basics, like planning for Bloodlust with your Elemental/Mirror Images/Icy Veins, proper management of cooldowns around trinket procs, proper boss timing to use elemental/mirrors to avoid AoE damage wiping them out, and so forth. Start with the basics go from there.

Stats (In Order of Importance)

Spell Hit (get to 368 no matter what) -Note: 368 assumes you took 3/3 Elemental Precision
Spell Power
Spell Haste
Spell Crit - Frost is less reliant on crits due to the shatter talent and Fingers of Frost. Stack all other stats first.

Recommended Glyphs

Summon Water Elemental
Frostbolt - Pure raiders only (losing the chill effect is terrible in 5-mans and solo questing)
Molten Armor/Evocation - More crit or all around utility of evocation that restores Hit points.

Recommended Enchants

Head - Arcanum of Burning Mysteries from Kirin Tor revered
Gloves/bracers/weapon +SP
Chest +8/10 stats
Cloak - Lightweave Embroidery (if tailor)/Greater Speed or Speed
Boots - Icewalker
Shoulders - +SP and crit from Scryers, Inscription, or Son's of Hodir
Leggings - Azure Spellthread/Sapphire Spellthread/Master's embroidery (If tailor)

Recommended Consumables

Tender Shoveltusk Steak
Spellpower Elixir
Flask of the Frost Wyrm

Additional Tips

You should be able to get around 1600-1800 dps on bosses with average gear and an average rotation ~1400SP, 350+ Hit. Try and get the Ebonweave Robe and gloves to boost your spell hit rating and the Scalpel from the Kirin Tor rep. Use Precision enchant on gloves instead of spellpower if needed to get closer to that hit cap. Perfecting your timing with Icy veins, elemental, Mirror Image, Cold Snap, trinket procs, etc. will boost you up towards 2k in no time. If you are having trouble meeting the hit cap while keeping up spellpower, run more heroics, pick up the emblem offhand and try to get the Mark of the War Prisoner trinket from Violet Hold. The offhand from Telestra in H Nexus is decent too.

Sources and Other Resources

I'm a fairly casual player, I PuG raids and heroics. DPS is typically in the 2500 range on raid bosses, my gear is very average compared to most raiders, but it works for me. Frostfire mages still beat me by 10-15% with similar gear. The hardcore raiders will think my gear is crap, but to the average casual player, most of my gear is highly obtainable and is not beyond your grasp. I got both my Valorous pieces from PuG 25-man VoA runs, where dps requirements aren't high. Frost spec is the easiest spec to play to hit passable dps levels for heroics and 10-mans. Simple rotation with decent results.

Check me out for spec and gear ideas. Most of my stuff is from heroics and emblems, a few pieces from PuG raids.