Shield Proficiency [General] Edit
You can use a shield and take only the standard penalties.
When you are using a shield with which you are not proficient, you take the shield’s armor check penalty on attack rolls and on all skill checks that involve moving, including Ride checks.
Barbarians, bards, clerics, druids, fighters, paladins, and rangers automatically have Shield Proficiency as a bonus feat. They need not select it.