Hallo :wave:
Beaver1337, making a guide on how what gems, glyphs and talents you shall have for your mage, both for PvE and PvP!
Better get going!
PVE
-Talents (Arcane) & Rotation
-Gems
-Glyphs
PvP
-Talents (Frost) & "Rotation"
-Gems
-Glyphs
PvE
Talents (Arcane) & Rotation
The talent that works best for a PvE mage is Arcane, without any doubt. If you are going to spec Arcane, this one is what i prefer:
Talent Calculator - World of Warcraft
The most epic rotation that i also use is the following:
4x ArcaneBlasts->/Repeat till Missile barrage procs/->Arcane Missiles->"Arcane Barrage"*. !Repeat from ArcaneBlast to 4x!
V->->->->->->->->->->^
* = Arcane barrage is good if you need to move while having the Arcane Blast 'debuff', then get a fancy crit and repeat, but go to 4 ArcaneBlasts, then when missile barrage procs, cast it and end with a Arcane Barrage.
Gems
Gems that you should aim for in PvE and is:
Runed Cardinal Ruby - +23 spell power | "Matches a red socket"
Reckless Ametrine - +12 spell power & +10 haste | "Matches a red/yellow socket"
Quick King's Amber - +20 haste | "Matches a yellow socket"
Glowing Dreadstone - +12 spell power & +10 stamina | "Matches a red/blue socket"
Those gems are the best for Arcane raiding, crit isn't that important for an arcane mage, so aim for spellpower and haste instead of socketing with crit.
Glyphs
The glyphs you should use is the following:
Major Glyphs:
"Glyph of Arcane Blast" - Increases your damage with 3% from the Arcane Blast (A Must!)
"Glyph of Arcane Missiles" - Increases your critical damage bonus from arcane missiles with 25% (A Must!)
"Glyph of Molten Armor" - Increases the molten armor's spirit with 20%, giving some crit.
"Glyph of Mana Gem" - Increases the mana you recieve from your mana gem by 40%
If i were a recently dinged 80 and doing some heroics / raids, i would go with the Mana Gem glyph instead of Molten Armor and replace it when you get some better gear with moar int and spirit. Do what you feel, you can buy the Molten Armor glyph aswell in the start.
Minor glyphs doesn't matter that much, but get the Arcane Intellect Glyph and Slow Fall, to save mana and slow the fall speed 
PvP
Talents (Frost) & "Rotation"
I choose frost as PvP-spec, since PvP is all about survival and *pew-pew* and what suits this better than frost?
Im not very into PvP anymore, so if this talent doesn't *roxorz*, feel free to post a better one so i can edit this here.
http://www.wowhead.com/?talent#of0Vf...0fdMfot:jmw0oz
With the "rotation", i more mean how to control your mage with attacks and such. Its fairly easy, when Fingers of Frost procs, cast 1x Frostbolt then another Frostbolt along with a Ice Lance. Then whenever Brain Freeze procs, just throw your instant fireball after your target! *mohaha* (If you have a brain freeze, try to land it on your last charge of Fingers of Frost, like this: *Fingers of frost procs*-> Frostbolt ->Frostbolt & Brain freeze, a very nice burst.
Gems
For PvP, you should go for the gems listed below. 'nuff said!
Mysterious Dreadstone - +12 spell power & +13 spell penetration | "Matches a red/blue socket"
Purified Dreadstone - +12 spell power & +10 spirit | "Matches a red/blue socket"
Runed Cardinal Ruby - +23 spell power | "Matches a red socket"
Reckless Ametrine - +12 spell power & +10 haste | "Matches a red/yellow socket"
Glyphs
As i have said and you probably understand, survival is the key to victory in PvP. So the following glyphs are good for PvPing as FROST, remember. Frost!
"Glyph of Ice Barrier" - Increases the damage your Ice Barrier absorb by 30%.
"Glyph of Icy Veins" - Removes all your movement imparing effects.
"Glyph of Blink" - Increases the distance by 5 yards.
"Glyph of Evocation" - Also heals you for 60% of your health.
Those four glyphs are the best but as i have said, im abit rusty with this PvP. The Evocation glyph is a must along with Ice Barrier, then imo i would take Icy Veins to escape the slowing effects. Its very useful! 
For minor glyphs you should get:
Glyph of Slow Fall, Glyph of Fire Ward and Glyph of Frostward.
Sidenote: PvP hit cap for spellpen. and hit: 4% for hit/130 spellpenetration.
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Thats it.. Or is it?
But.. Beaver1337, do you got another secret for us?!
Yes, i do. I was thinking for those who liked this guide and can't wait to level a mage ;D, i'll add a fast leveling guide in this post aswell!
Leveling a mage (Alt. with healer)
To start, this works best if you have a friend that can heal you without being in a party. In that case, you'll earn all experience from the mobs.
1-10. Just do the start quests! Do them... Cookies?
10-(~15) - Westfall, crab spot! Here is one of the best places to start. In Westfall is alot of crabs, that instant respawn(!) when you kill them. See map for location!

(15-16)-(~20-21) - Get boosted in Deadmines / Wailing Caverns. That is the best spot.
(~20-21)-30 - Duskwood. Go to Raven Hill and AoE farm those skeletons there, at 26-27 - go inside the tomb and AoE all ghouls there to 30.

30-(39-40) - The various Scarlet Monastery instances will go fast with a 80.
(Gy, Lib, Armory, Cath)
(39-40)-43 - Zul'farak or AoE the wastewander in the ruin west of Gadgetzan and at the camps!
43-49 - Feralas, yetis. Those are melee and is a great place to AoE farm!

49-54 - Searing Gorge. Do quests along with some AoE farming of the spiders, if you're out. Start moving to Stratholme / Scholomance.
54-(58-60) - Boosted in Stratholme / Scholomance. Its optional if you wanna go and quests in Outland at 58, might go faster.
(58-60)-(62-64) - Quest in Hellfire Peninsula and get boosted in Ramparts along with Blood Furnace.
(62-64)-66 - Quest in Zangarmarsh, do Slave Pens and Underbog if you can. If you ding 64-65, go Nagrand!
66-68 - Nagrand. Do quests and AoE farm the ogres there till 68. Then leave for Northrend.
68-73 - Quest in Howling Fjord / Borean Tundra.
73-(75-76) - AoE along with your homie-healer in the Scarlet Camps, Dragonblight.

(75-76)-79 - Quest in Grizzly Hills and Zul'Drak. There are pretty much melee mobs there.
79-80 - Quest in either Icecrown or Storm Peaks. Your choice.
And thats it. Pretty fast made 'leveling guide'. Just a bonus!
Bye everyone ! 
Edit: Thanks all for the feedback, especially for PvP !