Equipment refers to any item that can be equipped in an equipment slot, as distinguished from items that can only be carried in inventory.
Weapons
Warriors can use all weapon types except the Monk's specialty weapons known as Martial Weapons.
One Handed Edged (includes swords and axes) are usable by Dire Lords, Druids, Paladins, Rangers, Rogues and Wizards
Two Handed Edged (includes swords and axes) are usable by Dire Lords and Paladins
One Handed Blunt are usable by every class except for Dire Lords
Two Handed Blunt are usable by Clerics, Druids, Paladins, and Shamans
One Handed Staves
Two Handed Staves are usable by Enchanters, Summoners and Wizards
One Handed Piercing are usable by Enchanters, Rangers, Rogues, Shamans and Summoners
Two Handed Piercing
Martial Weapons are only available to Monks.
Ranged
Bows are usable by Rangers
Crossbows are usable by Rangers
The above weapons require to be used.
Thrown Items are such things as throwing knives, shurikens or even alchemical creations brewed by Rogues.
Armor
Armor comes in five types: Cloth, Leather, Martial, Chain and Plate. Mail and leather come in either Heavy or Light varieties. Some classes, such as the Shaman, only have access to the Light variety of an armor type.
Note: Clerics, Paladins and Warriors are capable of wearing all armor except the Monk's specialty armor known as Martial Armor.
Cloth armor is available to every class, but it is the primary armor type for Enchanters, Summoners and Wizards
Leather has two varieties: light and heavy.
Light Leather is the only type of leather armor available to Monks
Heavy Leather is the primary armor type for Druids.
Martial armor is a unique armor type exclusive to Monks.
Mail or Chainmail has two varieties: light and heavy.
Light Mail is available to Rangers, Rogues and Shamans.
Heavy Mail is the primary armor type for Dire Lords.
Plate or Platemail is the primary armor type for Clerics, Paladins and Warriors
Shields
There are two classifications of shields: Tower Shields and Bucklers.
Tower Shields are heavier shields and are usable by Clerics, Paladins and Warriors.
Bucklers are lighter shields, usable by those unable to wield tower shields.
Non-visible
Non-visible equipment are those items that can be equipped, but make no visual change to the character. Every class can ware non-visible equipment, with the usability varying item to item.
Below is a navigator for all equipment and weapon types.