From publisher blurb:
Upgrade Your Wizard's Staff!
Staff: the Weapon of Wizards introduces a new weapon for Pathfinder - the longstaff, a staff based on the historical medieval quarterstaff. According to the writings of the Renaissance arms masters, the quarterstaff was a weapon seven to eight feet long, wielded similarly to a spear or other pole weapon. The masters praise the usefulness of the staff as a weapon.
Beyond introducing the longstaff, Staff adds 11 new feats and a new druid spell.