Quicken Spells is a skill available in all spell schools. It requires 75 skill in the the school you want it in.

It will reduce the cast time of all spells in the schools you have it in, depending on the skill level of Quicken Spells you have in said school.
Your spells linked to Quicken Spells will have the same skill level as your Quicken Spells.
For the list of linked spells see Linked Spells

Magic Schools
Regeneration MagicRaw MagicInfliction MagicAir MagicEarth MagicFire MagicWater MagicSpell ChantingArcane MagicWitchcraftNecromancy
Magic skills
Durable SpellsMana EfficiencyQuicken SpellsIntensify Spells
Magic Global Skills
Veteran MageMana ConservationArchmageReagent Conservation
Linked Spells