Basic common information regarding a Power of Attorney in California

A power of attorney (POA) gives someone you name the authority to handle legal or financial matters for you under specific circumstances. When you create a POA, you are called the principal, and the person you choose to act for you is called your attorney-in-fact or your agent.
California Probate Code section 4123
4123. (a) In a power of attorney under this division, a principal may grant authority to an attorney-in-fact to act on the principals. behalf with respect to all lawful subjects and purposes or with respect to one or more express subjects or purposes. The attorney-in-fact may be granted authority about the principal’s property, personal care, or any other matter. (b) With regard to property matters, a power of attorney may grant authority to make decisions concerning all or part of the principal's real and personal property, whether owned by the principal at the time of the execution of the power of attorney or thereafter acquired or whether located in this state or elsewhere, without the need for a description of each item or parcel of property. (c) With regard to personal care, a power of attorney may grant authority to make decisions relating to the personal care of the principal, including, but not limited to, determining where the principal will live, providing meals, hiring household employees, providing transportation, handling mail, and arranging recreation and entertainment.  
Does a Power of Attorney have to be Notarized?
California Probate Code section 4121(c)
(1) acknowledged before a notary public or (2) signed by at least two witnesses who satisfy the requirements of Section 4122.  
California Probate Code section 4122
4122.  If the power of attorney is signed by witnesses, as provided in Section 4121, the following requirements shall be satisfied:
The witnesses shall be adults. The attorney-in-fact may not act as a witness. Each witness signing the power of attorney shall witness either the signing of the instrument by the principal or the principal's acknowledgment of the signature or the power of attorney.