Is there a way to do this?? It isnt very convenient to have to go into inventory, right click on the staff then select the spell u want to cast from it in the heat of battle. I tried to just put the staff into the quickslot, like you do with wands, but that doesnt work either, it just equips it.

yes! you put the staff in the quickslot. if its only got one spell, then you just left click the staff and it should change the mouse into the spell pointer thingy.

if it has more than one use, like the Staff of Defense, you stick it in your quickslot....right click on it to select the spell you want to use. it should bring up the circle menu, and the spells will be in the circle menu. left click on the one you want to select. then, just left click (or use the hotkey) to cast the selected spell.