There are two other roles you'll hear mentioned frequently.
Crowd Control Classes with Crowd Control (CC) abilities, such as traps or polymorphing, help manage multiple enemies in larger encounters. While these abilities are less integral in Wrath of the Lich King than they were in earlier versions of the game, there is talk that crowd control will regain some importance in future patches or expansions.
Hybrid While most classes have the ability to do at least some DPS along with whatever their primary purpose may be, a hybrid class is capable of filling any role efficiently, depending on gear and talents. The last two game expansions have stretched this definition out of shape, with players engaged in robust debate over who should do the best job versus who does do the best job at filling a given role. Plans to implement dual specs complicate planning for characters who value versatility. Bottom line: If you want to be able to try out different roles without creating entirely new characters, choose a class traditionally recognized as a hybrid, such as a Druid or a Paladin.
Class type Tank, DPS (melee)
Gear Death Knights can wear all armor types up through plate. They can wield most weapons except daggers, staves, wands and shields.
What's special about Death Knights? Death Knights are a hero class introduced in the Wrath of the Lich King expansion that start out at level 55. You can only create a Death Knight if you have a previous level 55+ character on any realm. DKs combine both DPS and tanking using a unique rune system to power their abilities. They are known for their strong solo capabilities as well as their ability to "snatch" enemies into melee range.
What are the drawbacks of Death Knights? Strategies and class balance for this new class remain unseasoned.
Is a Death Knight a good choice for a newbie? New players are not be eligible to create a Death Knight until they have reached level 55 with another character first.
Class type Hybrid, tank, DPS (melee), DPS (ranged magical), healer
Gear Druids can wear cloth and leather armor. They can use staves, one and two-handed maces, daggers, fist weapons and polearms.
What's special about Druids? In a word: shapeshifting. As you level, you'll gain the ability to run fast and hide like a cat, stand up to physical combat like a bear, swim like a fish (well, more like a manatee) and eventually fly like a bird (without a mount, unlike other players). Past the early levels, most Druids spend most of their time in one animal form or another (so if you're not fond of the racial choice available to your faction, take heart). You'll find yourself in bear form as a tank; in cat form as a Rogue-like physical DPSer; in Moonkin form as a spellcaster; or in Tree of Life form as a healer. Druids have a toolbox of crowd control capabilities, an excellent player buff spell and form-specific effects that buff other raid members.
What are the drawbacks of being a Druid? Some Druids-to-be are turned off by the fact that the Druid class is limited to one race per faction. Past that, the problem is more an overabundance of choice. Since Druids, as true hybrid classes, have so many options available to them, it may be tough to decide what role you prefer for your Druid. Still, decide you must – because the talent spec and gear choices you make heavily define what you're able to do. (For example, while you could drop to bear form and try to tank an encounter while specced and geared as a Balance Druid, you probably won't enjoy a large measure of success.)
Is a Druid a good choice for a newbie? Druids can be difficult to play in lower levels, before you get all of your animal forms. In general, a hybrid class requires a more complicated playstyle than a single-purpose class. Still, being a Druid does allow you to try out different roles as you level. At the end game, you'll be hailed as an outstanding healer, a valued spellcasting raid member, and a respectable physical DPSer or tank.
Class type DPS (ranged), CC
Gear Hunters can wear cloth, leather, and mail armor (the last starting at level 40). Mail provides both you and your pet with the highest armor rating. Hunters can wield two weapons at once starting at level 20. The only weapons they cannot use are wands and one-handed and two-handed maces. As a ranged damage-dealer, your main weapon will be a gun, bow or crossbow.
What's special about Hunters? A Hunter's pet is an integral part of the class. In combat, you'll use both your own abilities as well as those of your pet. It's a little bit like being part of a private two-player team. You'll be able to tame and train pets from the animals available throughout Azeroth, Outland and Northrend, each offering different abilities, advantages and disadvantages. Pets are usually used as tanks in solo play and DPS in groups or raids. Unlike other pet classes, Hunters can name and feed their pets. They can track monsters and players. Their trademark traps provide excellent crowd control, while others are designed for damage. Survival Hunters offer mana-restoring Replenishment, making them valued in raid groups.
What are the drawbacks of being a Hunter? Although you can melee, it's not your specialty. You'll want to stay removed from the action, with room to maneuver to place your traps and DPS from afar.
Is a Hunter a good choice for a newbie? Because of the "teamwork" aspect of your pet, you get the power of two players for the cost of one. Having a pet to tank for you while you stay back unscathed and DPS also makes for very easy soloing. At the end game, you'll be considered one of the highest DPS classes available.
Class type DPS (magical), CC
Gear Mages can use cloth armor and can wield staves, wands, daggers, and swords.
What's special about Mages? Mages are the class to pick if you're interested in playing a DPS spellcaster with big, flashy damage abilities. They are known for their burst and area (Area of Effect, or AoE) damage. Polymorph is a well-known and reliable crowd control method that temporarily turns targets into harmless sheep, turtles or other creatures. Blink lets you zoom out of melee range and tight situations, while portal spells allow you to teleport yourself and others all over the entire worlds. You'll be able to summon health- and mana-restoring food and drink. Frost mages can summon a Water Elemental that fights for 45 seconds, Arcane mages can Slow enemies, and Fire mages disorient opponents with fiery Dragon's Breath.
What are the drawbacks of Magedom? Mages are delicate creatures; they wear cloth armor and tend to have low health. Successful Mages learn to keep enemies at bay with crowd control techniques. Sometimes, a Mage's main strategy comes down to killing an enemy before it can kill the Mage first!
Is a Mage a good choice for a newbie? If you love huge bursts of damage and rains of area damage, you'll enjoy this class. If you can't get the hang of crowd control and keeping opponents at range, though, you may find yourself dying frequently – a prospect that's never fun.
Class type Hybrid, tank, DPS (physical), healing
Gear A Paladin can wear cloth, leather, mail and plate armor and carry shields. Paladins can use one and two-handed maces, one and two-handed swords, one and two-handed axes, and polearms.
What's special about Paladins? Paladins, like Druids, are just plain great at everything. Holy Paladins are considered the best tank healers in the game. Protection Paladins have carved out a niche as AoE (multiple-enemy) tanking specialists. Retribution Paladins deal respectable damage and offer raid-wide crit buffs and mana-restoring Replenishment, adding value to raid groups. In all three specs, your endurance in PvP approaches legendary levels, and your Auras and Blessings are highly desired in raids. You have access to quests that provide you with a class-specific mount.
What are the drawbacks of being a Paladin? Like Druids, you must ultimately decide what role you want to take on and then specialize (with both talents and gear) in order to be effective.
Is a Paladin a good choice for a newbie? Relatively low DPS makes Paladins slow levelers – a real killjoy, especially if you're just learning the game. Still, with heavy armor and great healing abilities, you're extremely difficult to kill, a nice bonus for a new player.