If you are not sure what class to pick when starting World of Warcraft or if you are looking for a strong alt, this guide gives a simple analysis of the strengths and weaknesses of each class. Since the classes are so different, choosing the right character from the start can you save a great deal of time. 

Warrior

Strengths:

1. Can wear mail from the start and plate at level 40.
2. Great melee abilities such as 
3. Great tank class, especially when using a shield and going deep into the Protection tree. 
4. One of the better classes to use for blacksmithing since warriors can use both the armor and weapons made with this profession.
5. Can be a force damage wise with a good two-handed weapon and a build focused on the Arms tree or two good 1 handed weapons and a build focused on the Fury tree. 
6. Can equip almost any type of weapon in the game whereas other classes are more restricted. For example, a shaman can not use a sword and a Paladin can not use a bow.

Weaknesses:

1. Depends on rage too much. 
2. Not a broad class. 
3. Not the highest melee damage dealer.
4. More equipment dependant than other classes.
5. Dependency on the healing of other classes.
6. Somewhat limited in PvP due to the range and magic of other classes.

Hunter

Strengths:

1. Having a pet that can serve as a personal tank.
2. Possibly the best solo class in the game.
3. Traps can turn the tide of a battle in PvP.
4. Tracking allows you to get a scope of enemies in the area.
5. Works great with the leatherworking skill.
6. A strong PvP class due to high damage and range. 
7. Can tame a huge variety of pets.   

Weaknesses:

1. Can not wear mail until level 40. 
2. Very few melee abilities.  
3. Can not use a shield. 
4. Pets can draw monsters to your group if not handled correctly.
5. Not sought after by groups.
6. Need ammo and food for the pet constantly.

Rogue

Strengths:

1. Best melee damage dealing class. 
2. Can open locks.
3. Great dual wielders.
4. Stealth opens up possibilities that other classes do not enjoy.
5. Possibly the most fun class in the game from a character ability standpoint. 

Weaknesses:

1. Can use no better than leather armor. 
2. Relies on daggers too much. 
3. One of the least respected and sought after classes in the game.
4. Very dependent on cool downs for abilities.

Paladin

Strengths:

1. Able to heal. 
2. Strong and durable enough to tank for a group.
3. Not dependent on rage like a warrior is or has to switch forms like a druid.
4. Gets the ability to summon a mount at level 40.  
5. Has abilities that allow the Paladin to be immune to attacks for a short period of time.
6. Can resurrect other players.
7. Can be very mana efficient if played right.

Weaknesses:

1. Lacks the overall damage of other classes. 
2. Both healing and tanking need to be focused on instead of trying to do both at once. 
3. Need to constantly manage blessings, seals, and auras.
4. Has a negative image on the Horde side due largely to "bubble and hearthing" (become immune to attacks and then using a hearthstone to leave the battlefield).  

Shaman

Strengths:

1. Can use mail as armor at level 40. 
2. Can use a shield while a hunter cannot. 
3. Can heal.
4. The best combo for a spell caster/fighter. 
5. Can self-rez and then resurrect the rest of the group.

Weaknesses:

1. Totems need to be managed constantly.
2. Due to the great flexibility of the class, it's hard to focus on just 2 or 3 attributes. 
3. Can not use weapons like swords and 2 handed axes.
4. Can dual wield only if going deep in the Enhancement tree.

Priest

Strengths:

1. The best healing class in the game. 
2. Strong defensive spells. 
3. Can do damage as well.
4. Highly sought after by groups.

Weaknesses:

1. Can only wear cloth. 
2. Not a role for everyone. 
3. Shadow priests can do more damage but are not near the healers as their holy counterparts. 

Mage

Strengths:

1. The best magic damage dealer. 
2. One of the best range classes along with hunters.
3. Good combat control with Polymorph.
4. Can summon food and drink.
5. A great choice for grouping.
6. Strong solo class due to snares and massive damages.
7. Can open up portals to go to major cities.
8. The best area of effect damage dealer in the game by far.

Weaknesses:

1. Can only wear cloth.
2. Not healers in battle. 
3. Major target for monsters due to high amount of damage.
4. Most damage dealing spells are not instant.

Druid

Strengths:

1. Able to take on the forms of different animals.
2. Can root enemies in place. 
3. Very flexible.
4. Can heal group members.
5. Good solo class.
6. Can tank if needed. 
7. Has different travel forms for faster traveling.

Weaknesses:

1. Cannot wear anything heavier than leather.
2. Not great at any one thing.  
3. Unpredictable for groups. 
4. Switching between the different forms to heal (regular), tank (bear), or damage (cat) can be awkward and time consuming.
5. Very difficult class to master.

Warlock

Strengths:

1. Has various pets. 
2. Can summon a mount at level 40. 
3. Great for debuffs. 
4. Can summon/teleport group members.
5. Great for crowd control.
6. Strong in both PvP and PvE.
7. Has a high amount of stamina.

Weaknesses:

1. Not as good a damage dealer as a mage.
2. Can only wear cloth.  
3. Hard class to play. 
4. Not one pet fits all situations.