I've just bought PF (and never played D&D before) and I've one question about Clerics: Can they cast spells with somatic component while using a One-Handed melee weapon and a shield?
Chapter 9 (Magic) reads:
Somatic (S): A somatic component is a measured and precise movement of the hand. You must have at least one hand free to provide a somatic component.
So I think they can't, but I'm not sure as they are a caster class with shield proficiency.