Weapons will give you a bonus in Physical Attack, and Magical Attack Power, sometimes Both, but not always. Some Weapons have an added Element that will harm those of the opposite Attribute at 2x the amount.

When attacking only if you are using the Weapon, will the Bonus be added to your Attack. However there are 2 Exceptions to this Rule.
1. If you use Magic to Attack, and have a Weapon that adds a Bonus to your MA, the bonus will be included in the attack. Note: Owning Multiple weapons will not increase the bonus.
2. If you are using Hands or Claws, a Glove/Gauntlet weapon, all Hand to Hand attacks will have a Bonus, this includes attacking with your feet or elbow or knee or shoulder ect. Note: If you are using Hands, you cannot wear Hand Protectors, Except for the Default, Glove Liner.

Some Weapons will grant your special Powers. Such as better Accuracy, Absorb, Cause Poison ect.
Accuracy is automatic, you'll have better chances of hitting your opponet (when using Dice).
Absorb is automatic, Whatever Damage you Cause, half of it will convert and restore your HP, if you cause 30 DMG, you'll restore 15HP.
Poison (Bad Status) will only take effect if you manage to get a critical it in. You must roll a 10 for it to poison your opponet. Poison will take away 10% of their HP until they die or are cured (Using Phych UP helps).

Buying and Selling:
Buying Prices are set, some Weapons cannot be bought, they either must be found in quests, or Made.
You can Buy a Weapon when you have the required amount of Golji; to buy one you can either do so Before the Quest starts, during the Quest (if you enter a town), after the Quest is over, or on the Forums.
You can always sell your weapons if you don't want them, the selling price is 1/2 of what you paid for it. You can sell at the same times you can buy. If you own a Store you may sell your weapons above the 1/2 mark, but it must be below the original price, if you bought something for 200g, you could sell it in your store for 150g, rather than 100g.

Lists & Info.
Swords Hammers Staffs Hands Knives & Daggers
Swords II Hammers II Staffs II Hands II Knives & Daggers II
Katana Clubs & Flails Whips Polearms Rings
Katana II Clubs & Flails II Whips II Polearms II Rings II
Crossbows Long Bows Arrows Guns Ammo
Crossbows II Longbows II Arrows II Guns II Ammo II
Claws Talons Boomerangs Slingshots Pellets
Claws II Talons II Boomerangs II Slingshots II Pellets II
Sai Scythes Axes Shuriken Blades
Sai II Scythes II Axes II Shuriken II Blades II
Rapiers [Empty] Sabers [Empty] Swallows
Rapiers II [Empty] Sabers II [Empty] Swallows II