Weapons are an important part of the game for many classes, and still an important piece of equipment for everyone else.
Your character will begin with a rudimentary weapon related to your class, (or two in the case of hunters.) As you use that weapon, you will become more skilled with that type of weapon. You will also be able to use other types of weapons, some of which you are already proficient with and some of which you will need to learn proficiency. Other weapon types may be completely unlearnable.
Axes, maces, swords, daggers, and fist weapons are all one-handed. Two-handed axes, two-handed maces, two-handed swords, staves, and polearms are all two-handed. Bows, guns, crossbows, and wands are all ranged weapons.
Several important notes about this information:
Every weapon is unique. In addition to being a standard piece of equipment, with the normal attributes that equipment often has, a weapon will be in one of 13 categories. Additionally, each weapon will have a damage range it will do naturally when striking, and an attack speed. Based on these two pieces of information, the game will also provide a Damage Per Second value.
Generally speaking, a character will consider a weapon an upgrade when the DPS value is higher. This means the rate of damage being dealt is higher. There are some obvious exceptions, however:
|Guns, Bows, and Crossbows||X||-||-||O||X||-||-||-||-|
To learn a skill your character is able to learn, but does not possess, you must visit a weapon trainer. You will find at least one of these individuals in each major city, and the guards will give you directions to them. Unfortunately, weapon trainers do not specialize in every single type of weapon that exists. However, they will also inform you of which other weapon trainers you might be interested in visiting.
When a player first begins to work with a weapon, they will have a skill rating of 1. At level one, this would be a skill of 1 out of 5 (1/5) in the Skills Menu. When a player is less accomplished with a weapon, they will miss almost exclusively against higher-level targets until their skill climbs to a level where it approaches five times the target's level. They will also be incredibly unlikely to score a critical hit. Fortunately, at this stage, their weapon skill will go up with nearly every use of the weapon.
When a player's weapon skill matches his opponent's Defense, he should have a 5% chance to miss. Targets higher than your level will always have more defense than your weapon skill, and so this chance to miss is noticeably elevated. Until patch 2.3, there were means in the game to raise one's weapon skill through Racial Bonuses and stats on items. (These have since been replaced with the attribute of Expertise.)
There are other items that can be equipped in some of the weapon slots. Many of these are caster-oriented items that state "Held in Hand". These items are intended to be equipped in the off-hand. Even more common that those are Shields, which warriors, paladins and shamans can use for a stupendous bonus to their armor.
Without access to missile weapons or wands, the three hybrid classes, (druid, paladin and shaman,) have nothing they are able to equip in their ranged slot. As a result, Blizzard has a few special items that these classes can use for very specific bonuses. The actual name varies per class, but generally these items are referred to as Relics.