Listed here is a database of classes available for use:
Engineer (Cleric) (Player's Handbook, page 60; Essentials: Heroes of the Fallen Lands, page 80)
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Engineers act as both mechanics and divine healers, aiding both machine and flesh.
Engineers have Mechanic and Science added to their Trained Skills list.
Soldier (Fighter) (Player's Handbook, page 74; Essentials: Heroes of the Fallen Lands, page 122)
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Soldiers are warriors, usually either fighting as part of a military organization, or working as mercenaries, just to name a couple examples.
Soldier's have Mechanic added to their Trained Skills list.
Knight (Paladin) (Player's Handbook, page 89; Essentials: Heroes of the Fallen Kingdoms, page 117)
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Knights are similar to soldiers, though much more adept at using the divine might of the gods to aid them in battle. In Vector Terra, they act under the command of either the military, or a church.
Knights have Mechanic added to their Trained Skills list.
Ranger (Player's Handbook, page 103; Essentials: Heroes of the Fallen Kingdoms, page 148)
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Rangers are those who are skilled either with long range weaponry, or wielding two weapons at once. There are also some rangers who travel with a favored animal companion, such as a wolf or a hawk.
Thief (Rogue, Player's Handbook, page 116; Essentials: Heroes of the Fallen Lands, page 168)
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Usually known for their acrobatic feats and sleight of hand maneuvers, thieves are very crafty and know how to pull off a heist, whether big or small.
Thieves have Science added to their Trained Skills list.
Warlock (Player's Handbook, page 129; Essentials: Heroes of the Fallen Kingdoms, page 200)
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Warlocks are arcane spellcasters who make pacts with beings of other planes to gain their powers.
Commander (Warlord, Player's Handbook, page 143)
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Usually seen leading their troops, commanders provide aid to any and all allies on the battle field.
Commanders have Mechanic added to their Trained Skills list.
Wizard (Player's Handbook, page 156; Essentials: Heroes of the Fallen Lands, page 192)
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Having spent a great deal of time studying magic, wizards have gained vast knowledge of many things, including the arcane arts.
Wizards have Science added to their Trained Skills list.
Avenger (Player's Handbook 2, page 32)
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Like Knights, Avengers also serve the church, usually paired up with a Knight for tasks.
Avengers have Mechanic added to their Trained Skills list.
Berserker (Barbarian) (Player's Handbook 2, page 48)
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Primal warriors who tap into their own rage to unleash powerful strikes. Commonly found amongst the races not-so-technologically-advanced, but not limited to them.
Musician (Bard) (Player's Handbook 2, page 66)
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Musicians use music to fuel their powers, whether it's a musical instrument, or their own voice.
Druid (Player's Handbook 2, page 82; Essentials: Heroes of the Forgotten Kingdom, page 82)
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Druids command nature to strike at their foes. Some druids can also gain an animal companion, a creature they form a special bond with, or outright transform into a creature of their choosing.
Invoker (Player's Handbook 2, page 100)
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Invoker's are spellcasters who, instead of relying on arcane might, have follow the path of religion to aid them in battle.
Shaman (Player's Handbook 2, page 118)
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Primal leaders who call upon animal spirits to aid them in battle against their foes.
Sorcerer (Player's Handbook 2, page 136)
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Mighty spellcasters who's powers are almost used solely for destruction.
Sorcerers have Science added to their Trained Skills list.
Warden (Player's Handbook 2, page 152)
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Wardens can channel the animal spirits into their own attacks, or even shape shift into powerful guardian forms.
Ardent (Player's Handbook 3, page 22)
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Ardents use their psychic abilities to empower allies and infect enemies.
Ardents have Mechanic and Science added to their Trained Skills list.
Battlemind (Player's Handbook 3, page 42)
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Battleminds wield both cunning intellect and physical might to crush their enemies.
Battleminds have Mechanic and Science added to their Trained Skills list.
Brawler (Monk) (Player's Handbook 3, page 62)
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Brawlers are warriors capable of dishing out as much damage with their fists as a soldier would with a sword. Some brawlers belong to monasteries and live their lives as monks, training their body, mind, and soul.
Brawlers have Mechanic added to their Trained Skills list.
Psion (Player's Handbook 3, page 80)
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Psions are telekinetic, using their minds to both move objects and manipulate foes.
Psions have Science added to their Trained Skills list.
Runepriest (Player's Handbook 3, page 98)
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Runepriests use runes to bolster their abilities, as well as aid allies and hinder foes in battle.
Hunter (Seeker) (Player's Handbook 3, page 116)
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Hunters focus mostly on ranged combat, fusing primal spirits to empower and guide their shots.
Assassin (Dragon Magazine issue 379, page 16; Essentials version: Dragon Magazine issue 394)
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Assassins are hired killers, using stealth and the shadows to wipe out their targets.
Assassins have Science added to their Trained Skills list.
Alchemist (Artificer) (Eberron Player's Guide, page 44)
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Alchemists can create potions and magic items, summon their own inventions to support others, and enchant allies with various benefits.
Alchemists have Mechanic and Science added to their Trained Skills list.
Swordmage (Forgotten Realms Player's Guide, page 24)
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Swordmages use a special type of sword style, channeling magical energies into their blades while teleporting to an ally's side to protect them.
Swordmages have Science added to their Trained Skills list.
When filling in your character sheet, if using the actual name given in the books makes it easier for you for any reason (such as remember what powers you take or whatever), feel free to list the book's name on your character sheet. These changes were simply done for flavor and have no impact on gameplay elements.
