Diablo 3 Blog Guide

 Wizard Spells and Damage guide

 Diablo 3 Weapon Science Guide

 Weapon Damage Calculation Video

 Diablo 3 Damage Calculator

 DPS Calculator

 DPS Chart

Wizard and Witch Doctor weapon damage system explanation submitted by trog: 

Each weapon has three relevant base stats: 

Minimum damage

Maximum damage

Attack speed

The tooltip also displays average DPS, which is actually a red herring: the min/max/AS numbers are much more relevant. If you have a 1.0 AS staff that does 20-30 damage with 20 intelligence (and you have no other int), that means that each hit will roll a random number between 20 and 30 and then that number will be multiplied by 1.2 (remember, each point of int is +1% damage).

Effective Damage Range: The effective damage range of that weapon for a Witch Doctor or Wizard is actually 24-36. Your "Damage" stat in the character sheet factors this in and spits out an average DPS stat accounting for all modifiers: in this case, you'd see a damage stat of 30. Of course, the damage stat is just a guide: whenever you use a skill, it grabs a random number from the damage range and then applies all bonuses and modifiers-- the Damage stat has very little correlation to the size of a single hit!

If you had a different 1.0 AS weapon that had a damage range of 25-37 but no Int, it would do more damage because the base DPS is more than 20% higher.

This is also why those +1-2 damage rings are so good in early Normal mode. A normal one-hander blue before level 20 is gonna rock something like 18 DPS (example:17.5DPS 10-17 damage range 1.3AS Axe). If you're using that axe and you slap on a pair of 1-2 damage rings, it goes to 12-21 damage or 21.45 DPS, albeit with higher variance than before. Those crappy little rings are worth 22 intelligence in this scheme!

This system is also why you such strange outliers in terms of DPS. Ceremonial Knives always seem like they've got insane DPS, right? Well, they do, but they also have stupid high variance. A white level 24 Ceremonial Knife has a damage range of 10-37; a comparable level 22 mace has a damage range of 18-32, meaning that hits will be much more consistent.

Witch Doctors with Knives probably notice that sometimes a Firebat will one-shot foes and sometimes it'll half-health them-- it's thanks to the variance. In general, high variance is fine on fast, cheap attacks, and awful on slow, expensive ones.

Here is another guide about weapon damage. Thanks to qp0n for the following guide:

Figuring out the basics is easy once you figure out the damage multipliers.

There are only two things that get tricky for the average player:

1 ) Flat +damage stats will always add identical total damage to your 'weapon damage', but the DPS added depends on the weapon speed. Adding +10 damage to a 1.50 dagger will add 15 DPS because that 10 damage is applied 1.5 times per second, whereas a 1.00 staff would only gain 10 DPS, despite both weapons gaining exactly +10 weapon damage.

Spell damage won't be changed however since it is calculated using weapon damage not DPS. The difference in DPS is made up for with casting speed.
and

2) Faster weapons are not necessarily better than slower ones, and vice versa. The 'weapon damage' that spells use to calculate "X% of weapon damage" is not using your DPS but your actual damage per 'hit'.

If you have two weapons like the two mentioned above and both have exactly 90 DPS, but at 1.50 and 1.00 speeds respectively... the former will have 60 weapon damage and the latter 90 weapon damage. Meaning spells using the staff will do more damage, but the dagger will allow the casting of successive spells 50% faster.

For #2 the tradeoff comes down to your Arcane Power pool and cooldowns. There technically wouldn't be any difference between the two weapons in a straight resource-free, cooldown-free nuke test ... but since your AP is finite and some damage spells have cooldowns, you may want to get the most damage out of those casts rather than the ability to cast quicker.

In that case the slower weapon will deal the most damage. Or you may prefer faster casts to proc any number of things such as AP regen on hit. It's all preference.

(Personally I prefer the slower the better, biggest bang for the buck. So don't laugh if I join your group carrying a 2H samurai sword!)

Wizard Attack speed Test

This is the future page of the Wizard class! We apologize there isn't more stuff here yet, but check back soon.

Diablo 3 Wizard Guides

Also check out the Diablo 3 Wizard Builds section.

Wizard Inferno Build

In the meantime, check out Blizzard's guide to the Wizard!

Thanks to LT for this tip. Below is an explanation by LT of what elective mode is and why it is beneficial to new Diablo III players.

What is elective mode (Short version)

Elective mode is an option that is turned off by default. It is highly recommended that you toggle it on as soon as possible.

Elective mode allows the player to place multiple skills from the same category to their key bindings.

What is elective mode (Long version)

By default, the attack buttons in Diablo 3 are bound to the following: Left mouse button, right mouse button, and the 1, 2, 3, and 4 keys on the keyboard.

The skills in Diablo 3 fall into six categories. These categories vary by class, but every class has six. For the sake of simplicity, we'll be using the wizard as an example. The wizards six categories are: primary, secondary, defensive, force, conjuration, and mastery.

With elective mode off, a wizards primary skill must be bound to the left mouse button, a secondary skill must be bound to the right mouse button, a defensive skill skill must be bound to the 1 key, a force skill must be bound to the 2 key, a conjuration skill must be bound to the 3 key, and a mastery skill must be bound to the 4 key.

By extension, it means the player can only use one skill from each category when selecting which six skills to use. Once they choose a primary skill, that is the only primary skill they can use until they switch it out with another primary skill.

With elective mode on, the player is allowed to place multiple skills from the same category on their bindings. A player could use four primary skills if they so desired. For example:

http://us.battle.net/d3/en/calculator/wizard#UZXlQk!WcX!YbZcZY

A basic ice wizard build with elective mode on. The player has selected both two defensive and two force skills. With elective mode off, this would not be possible since the player would be forbidden from using multiple skills from the same category.

In essence, elective mode being off greatly limits your skill choice, and by extension, customization. It is highly recommended that you turn it on as soon as possible.

How do you turn elective mode on?

Once you join a game, simply hit escape, go to options, go to gameplay, and toggle the elective mode box.

Here is a great Witch Doctor build (build is at around level 30)

Skill setup:

Poison dart + Mana rune
Flaming skull + Jumps up to 8 times
Locust swarm + double-jump rune
Wall of Zombies - Lock out that horde of enemies and watch them melt due to your locusts
Gargantuan - Big boy picks up the slack and gives you more survivability
Intelligence buff Aoe + Mana steal (you really need a lot of mana as WD)

Passives:
Mana/Life regen upon health globes
+20% damage, +30% mana cost.