First off, this is completely my own work, not just some copy and paste off of some sites, it is based on my experience with each spec I have used so far on my mage. So... lets begin!
First Specc: 31/20/0
About this Specc: This specc dishes out a LOT of damage in a short amount of time. There is an obvious combo here that involves Presence of Mind, Arcane Power, and Pyroblast. It enables you to do a souped up version of Pyroblast INSTANTLY! Combine that with +damage gear, and a pot, and you will one shot lots of people.
ARCANE
5/5 Improved Arcane Missiles- Cannot be interrupted while castin Arcane Missiles.
5/5 Arcane Concentration- 10% chance to proc Clearcast(next spell is mana-free)
3/5 Magic Absorption- Increases all resistances by 6 and restores 3% of total mana when you resist a spell
3/3 Improved Arcane Explosion- +6% crit chance on Arcane Explosion (AoE)
1/1 Arcane Resilience- Increases Armor by 1/2 your amount of intellect
2/2 Improved Mana Shield- Decreases mana lost from Mana shield by 20%.
1/1 Presence of Mind- Next spell cast within a 10 second casting time is instant.
2/2 Improved Counterspell- Your counterspell technique has 100% chance to silence target for 4 seconds.
5/5 Arcane Mind- Increases maximum mana by a big 10%!
3/3 Arcane Instability- Increases all spell damage and crit% by 3.
1/1 Arcane Power- While active, all spell damage is increased by 30% at the cost of 30% more mana to cast. Effect lasts 15 secs.
FIRE
5/5 Improved Fireball- Casting time for Fireball is reduced by 0.5 seconds.
5/5 Ignite- Crits from fire spells cause the enemy to burn for 40% of the total damage over 8 secs.
2/2 Flame Throwing- Increases range of all fire spells by 6 yards.
3/3 Improved Fire Blast- Reduces Fire Blast's cooldown by 1.5 secs.
2/2 Incinerate- Increases 4% crit on Scorch and Fire Blast.
1/1 Pyroblast- Hurls and immense boulder, that does 716-890 fire damage, and an additional 268 over 12 secs.
2/3 Improved Scorch- 66% chance to make the target vulnerable to fire, increasing damage by 3%. Stacks up to 5 times.
Second Specc: 20/0/31
About this Specc: This is my favorite specc to AoE farm with! It enables you to freeze your target(s) and in doing that give you a higher crit percentage. Also, if you are fighting magical targets, with the Imp. Dampen Magic, they won't do as much.
ARCANE
5/5 Improved Arcane Missiles- Cannot be interrupted while castin Arcane Missiles.
5/5 Arcane Concentration- 10% chance to proc Clearcast(next spell is mana-free)
1/1 Arcane Resilience- Increases Armor by 1/2 your amount of intellect
3/3 Improved Arcane Explosion- +6% crit chance on Arcane Explosion (AoE)
2/2 Arcane Attunement- Increases the effect of Dampen Magic and Amplify magic by 50%.
2/2 Improved Counterspell- Your counterspell technique has 100% chance to silence target for 4 seconds.
2/3 Arcane Meditation- 10% of your mana regeneration continues while casting.
FROST
5/5 Improved Frostbolt- Reduces casting time of Frostbolt by 0.5 seconds.
2/3 Elemental Precision- Reduces the chance your Fire and Frost spells can be resisted by 4%.
3/3 Frostbite- Gives chill effects 15% chance to freeze the target for 5 more seconds.
2/2 Improved Frost Nova- Reduces cooldown of Frost Nova by 2 secs.
3/3 Permafrost- Increases duration of all chill effects by 5 seconds and reduces the target's speed by an additional 10%.
1/1 Cold Snap- When activated, all Frost spell cooldowns are finished.
5/5 Shatter- Increases crit% by 50% with frost spells against frozen targets.
1/1 Ice Block- When activated you turn into an block of ice, granting immunity to any physical and magic attack for 10 secs.
3/3 Improved Cone of Cold- Increases damage with Cone of Cold by 35%.
5/5 Winters Chill- Frost spells have 100% chance to apply Winter's Chill, which increases crit% on all frost spells by 2%. Stacks up to 5 times.
1/1 Ice Barrier- Instantly shields you, absorbing 818 damage, and your spells can't be interrupted.
Well, I have to go soon, I'll write more later when I get the money to try out a new specc again =). Thanks for looking at my guide and I hope that you put it to good use!
EDIT:::: My full guide is more down.