how am i going to use staff as my weapon i cant do it i really didn't know how help plz

First you will have to train that skuill -> go to weapon trainer in major city (ask guards there). And then just equip and use.

Have fun...

as the above poster said, you need to train first.

If you were asking how to actually hit the enemy, just right-click the target

Staves are taught in thunder bluff if that will save you some time

hi i'm a 32 lvl holy+disc priest which weapon i must use STAFF or MACE?

depends, do u have an offhand item, do u have a GREAT staff/mace

In general and at higher levels maces will give you more +healing, while staves will give you more + other stats.

So, it basically is up to you.
I personally have both mace+offhand and staves. The use depends on what I will have to do: group healing (-> mace + OH)or just some soloing (-> staff).

This is mostly accurate.  In general, a Main Hand / Off Hand combination will give a caster more Healing/Damage than a Staff will, but the Staff will give more other Stats.  This much is true, but the simplified uses you describe aren't entirely accurate.

For instance, I tend to use a Main/Off when healing in a raid because most fights don't require me to stack Stamina, and I generally have a Shadow Priest in my group, so regen isn't a concern, so I might as well have more +Healing.  In some fights, having that extra Spirit or Stamina is relevant, so a Staff may be warranted.  Prior to 2.4, I would carry both a staff with good regen and a Main/Off combination with good +Healing.  Post 2.4, I have so much regen that the regen from the staff no longer made enough difference in such fights that it was worth the nerf to my healing in mana intensive fights.  Instead, I now use that Main/Off Combination for both, and in fights where HPS is more important than HPM, I stack Spell Haste at the expense of Intellect and Spirit.

As for soloing, I actually have an entirely seperate epic DPS set specifically for soloing (hell, it's good enough I can even adequately fill a DPS slot in most heroics).  That said, comparing DPS Main/Off to Staves is a lot harder, and almost always favors Main/Off because the relative value of +Damage is higher than +Healing, and the usefulness of secondary stats and regen is relatively lower.

As a cloth wearer , I would take all of the available weapon's training , available . The staff training will allow you to pick " need or greed " on a Blue item staff in Uldaman . It's attribute's are more of a druid's drop , but is definately worthy for priest protection .

LOL dude you should really ask someone in the game about it before you post it on thottbot and BTW you should know already your a friekin level 32 i am lvl 20 holy and I already know rofl lmao.