Classes
WoW Forever class guides: rotations, builds, every ability with a write-up, a talent calculator and what changed from Classic.
Warrior
Warriors are rage-fuelled melee fighters that excel as tanks or two-handed/dual-wield damage dealers. Forever makes Tactical Mastery baseline so stance dancing keeps rage, reworks Slam into an 18 sec cooldown strike (Improved Slam no longer resets your swing), and adds Spearing Strike for dismounting and hitting giants.
Paladin
Paladins are plate hybrids that heal, tank and fight in melee with Seals and Judgement. Forever overhauls them heavily: the new Light's Vigil turns the level 40 Holy Shock talent into group healing, Protection gets Seal of Fury, Judgement of Fury, Hammer of the Righteous and Templar's Bulwark, and Retribution gains Holy Strike and Twist of Light seal echoes (Twist of Light is in Blizzard's notes, but the client does not show how to learn it).
Hunter
Hunters are ranged physical damage dealers with pets, traps and stings. Forever adds Summon Hawk (a hawk dive-bomb sharing Arcane Shot's cooldown), melee attack power on Aspect of the Beast, Sniper Shot and a real melee Survival toolkit with Strider Kick, Lacerate and a weapon-based Counterattack. Aimed Shot now shares its cooldown with Multi-Shot.
Rogue
Rogues are energy-based melee assassins built around combo points, finishers and stealth openers. Forever gives them Mutilate and the Venom finisher (boosting poison damage and application), Coup de Grace for Deadly Poison Eviscerates, Puncturing Wounds for Backstab and Mutilate crits, and a Flawless Execution passive to cheapen Eviscerate that no trainer teaches yet.
Priest
Priests are cloth healers and shadow casters. Forever gives them a large new toolkit: Penance for Discipline, Prayer of Mending and Binding Heal for Holy, and baseline Shadow Word: Death for Shadow. Several new spells are racial: Contingency Plan and Confounding Flash (Gnome), Divine Grace (Human), Dark Sacrifice (Undead) and Chastise (Dwarf). The client also has a Litany of Light passive that no trainer teaches yet.
Shaman
Shamans are totem-based hybrids that heal, cast elemental spells or fight in melee. Forever adds Lava Burst for Elemental, Riptide for Restoration and quality-of-life totem tools: Call of the Elements, Call of the Ancestors and Call of the Spirits drop up to four totems in one 3 sec cast, and Totemic Recall returns them for mana.
Mage
Mages are pure ranged casters with strong AoE, crowd control and burst. Forever adds Arcane Blast (stacking buff to your other spells), Ice Lance (300% more damage on frozen targets) and Frostfire Bolt (a frost and fire hybrid bolt with a DoT and slow), each feeding its tree's talents.
Warlock
Warlocks are DoT and shadow casters with demon pets and strong self-sustain via Life Tap. Forever splits Curses and Banes (Bane of Agony and Bane of Doom can stack with a Curse like Curse of the Elements), adds Wrack as a channelled Affliction DoT amplifier, and adds Incinerate and Bane of Havoc for Destruction alongside the level 40 Conflagrate talent.
Druid
Druids are shapeshifting hybrids that can heal, tank in bear form, fight in cat form or cast as Moonkin. Forever adds a real bear toolkit with Lacerate, Primal Bite and a trainable Feral Charge, and gives Restoration Wild Growth and the out-of-combat Revive. Insect Swarm is still a Restoration talent.