Translated automatically from Italian: talent and ability names stay in English, as in the game. Original text (Italian) →
This build takes the Mage to 60 with Frostbolt, freezes and Ice Lance, and puts nine points in Arcane for Missile Barrage, which gives you Arcane Missiles at no mana cost. You keep enemies at range, slow them down and hit them hard while they're frozen; it also holds up well in dungeons.
How to play it
This build is all about range: the enemy comes at you slowed, gets stuck in the ice and takes your hardest hits right while it's frozen. Early on you have to ration your mana, but around 30 the rotation starts to work, and with Fingers of Frost it flows smoothly, even against several enemies.
The path, level by level
10–11: two points in Precision, to reliably hit enemies of your level right from the start.
12–18: Wand Specialization and Improved Channeling, then Missile Barrage: every Frostbolt can give you a free, faster Arcane Missiles. It's the build's biggest mana saver and worth the delay in the Frost tree.
19–26: Improved Frostbolt, for a faster Frostbolt, and Frostbite, which can freeze the target with your slows.
27: Ice Lance, which in Forever is a talent with a cooldown.
28–35: Ice Shards and Shatter, the engine of your crits on frozen targets.
36–38: one point in Improved Blizzard, which gives Blizzard a slow and therefore more freezes and more Fingers of Frost; then Fingers of Frost, and this is where the build really comes together.
39–47: Arctic Reach (range), Frost Channeling (less mana), Ice Block and Permafrost (with Cone of Cold you keep about 4 enemies slowed at all times), then Cold Snap and Ice Barrier, a shield that also raises your Frost damage for one minute: keep it up at all times. Arctic Reach, Frost Channeling and Permafrost are the most flexible points.
48–50: two points in Arcane Subtlety, which lowers the target's resistances, and the third point in Precision.
51–58: Improved Cone of Cold and Winter's Chill: Frostbolt and Ice Lances empowered by Fingers of Frost stack Winter's Chill, which strengthens your next Cone of Cold.
59–60: Improved Frost Nova.
How a fight plays out
Open from max range with Frostbolt and keep casting it while the enemy walks toward you. When Frostbite freezes it, cast Frostbolt and press Ice Lance just before the cast finishes, so both hits land together; with Ice Lance on cooldown, use Cone of Cold. The two Fingers of Frost charges go on a Frostbolt and then on Frostbolt plus Ice Lance. Fire the free Arcane Missiles from Missile Barrage, but save them for the next enemy if this one is nearly dead. If something reaches you, Frost Nova or Blink and start over. The killing blow belongs to your wand or Fire Blast, not to a full Frostbolt: your mana regeneration starts again sooner.
Three or more enemies
Flamestrike before they arrive, if it's safe. Then Cone of Cold as soon as it's ready and on every Fingers of Frost, Blizzard in between to trigger freezes and charges, Arcane Explosion when they're on you and you can't channel.
On gear, hit comes first, up to the cap (Precision is enough against enemies of your level, bosses of level 61 and above ask for more), then spell damage and Frost damage, which in Forever also raises your wand damage, then crit, because Ice Shards doubles the damage of your Frost crits. Spirit, Intellect and Stamina come after, in that order.
Strengths
High damage on a single target and on groups alike.
Slows and freezes are part of the rotation: you control the fight while dealing damage.
Scales extremely well with gear.
Missile Barrage adds free Arcane Missiles to the rotation.
Conjured food and water, teleports and portals: lots of utility for you and your group.
Weaknesses
Uses a lot of mana.
Only performs at its best with good gear.
Needs its talents: it starts to click around 30.
Part of the damage depends on random effects like Frostbite and Fingers of Frost.
Cloth wearer: if enemies reach you, you go down fast.
Notes
Wand: get a Lesser Magic Wand at 5 and a Greater Magic Wand at 13. They're cheap on the Auction House, because enchanters craft them to raise their skill.
Buffs: Arcane Intellect up at all times, and Frost Armor while questing, because its slow on whoever hits you can trigger Frostbite. Mage Armor only when you know you won't be hit.
At the start of each session, conjure food, water and a Mana Gem.
Spell batching: in Forever an instant spell pressed just before a cast finishes resolves together with that cast. It's the trick behind the Frostbolt plus Ice Lance combo.
Dungeons: in Forever their experience comes mostly from quests. Gather them all and run each dungeon once.
Teleports come at 20: don't bind your Hearthstone to a city you can teleport to.
When paired with another player, this build's AoE damage lets you pull much larger packs.
At 60, for raids, it's better to switch to another build.
Race: Gnome, if you play Alliance.
