Dagger - any weapon longer than 12 inches but shorter than 18 inches. The weapon is used in one hand, and does not require the other hand to be free to use.
Hand and a half - any weapon longer than 36 inches, but shorter than 48 inches. The weapon can be used one handed or two handed, but the player may not have anything else in their other hand. Sometimes called a 'bastard sword'.
Two handed - any weapon longer than 48 inches, but shorter than 96 inches. To use two handed weapons the player must have both hands. Other weapons cannot be held in either hand. Attacks must start with both hands on the weapon, but the player does not have to keep both hands on the weapon during the attack. If both hands are holding the weapon, both hands gain 'Hand on weapon'.
Ranged weapons - generally there are no length restrictions associated with ranged weapons. Bows should be under 30 lb pull. Do not aim at the head with any type of Ranged weapon. For most boffer arrows you can make due with a 10 lb pull fiberglass bow, so 20lbs or 30lbs are a bit overkill. If you're using a 30 lb pull bow make sure you do not pull the string all the way back. This can be accomplished by constructing arrows which are shorter than a full draw.
Throwing weapons - Any one handed weapon specifically constructed to be thrown safely can be used as a throwing weapon (more about this in weapon construction rules). Do not aim at the head with any type of thrown weapon. Generally they should be 18 inches or less, but that's more for practicality than functionality. While it's possible to build a two handed throwing spear safety, it would be pretty useless on the battle field. Some latex throwing weapons are longer than 18 inches, which is fine, as those types of weapons have no exposed pipe.
Two weapon fighting - Daggers and one handed weapons can be used 'Two Weapon' style. This means that a player can hold one in each hand. This could be dagger/one handed, or two one handed weapons. Playing with a weapon in each hand is extremely difficult and takes a while to learn. Some people have a taste for it, most don't.
You could consider 'Sword and Board' as the same classification as Two Weapon. Shields count as a one handed weapon regardless of being a target buckler (12 inch diameter) or a kite shield. Some shields may be constructed with striking surfaces, if so check with a Marshall to make sure it is safe before fielding the shield/weapon.
Generally being shown how to build boffer weapons is much more informative than attempting to learn the rules and steps alone. Fortunately there are plenty of guides and videos online about how to construct safe boffer weapons. If it's safe for another game systems it will probably be fine for our practice.
If you have any specific weapon questions, or if I have forgotten some specific weapon rule, you can tweet me directly @jspringfied211. You can comment, ask questions, and provide suggestions for this post on my Google Plus feed (it attracts less spam than my website). There is a FB group for the practice.And finally you can find me on Ello.co as @larp.