You DO need to understand that there are two types of POA: One is the unlimited general powere of attorney where you give someone complete authority over ALL your legal transactions... Due to the sweeping scope of this form of POA, I would recommend you be extremely cautious before granting ANYONE this much authority in your dealings.
The other form of POA is a LIMITED Power of Attorney, and it grants authority only to act on your behalf for specified acts or types of transactions, so if you wanted someone to act on your behalf for example say, the sale of a piece of property...you would specify in the POA the exact transaction that the power is granted for. You can also specify time frames within which it is in force, from such and such date until another ending date.
You kind find POA kits in most office supplies and in that section of Walmart or Target, and also online, just to name a few places the forms can be found.
The form will need to be witnessed in front of a notary public and also
be notarized by that notary before it can take legal effect.
Both forms of POA can be revoked by a simple signed statement revoking the power, also notarized, and sent by certified mail or hand delivered to the recipient, with a statement (certificate) of service stating when and how the revocation was presented to the recipient (certified mail or hand delivered), and said revocation should also be published under the legal matters heading of the local newspaper classified ads.
Not too complicated, huh?