What kind of POA do I need to give my aunt in order for her to be able to sell my father's house in a different state than where I reside?

You would advise you to deal with this situation as follows.  While you are marketing the house, you do not need to give a power of attorney to your aunt.  It is usually best to stay involved with the marketing process.  When you and your aunt list the property with a broker, it will be necessary for both of you to sign the listing agreement and probably some disclosure forms and other documents relating to the listing and marketing of the house.  Since you are living in another state you should ask the broker to send you the documents so you can sign and return them.  Then, if there is a need to revise or renew the listing agreement or if you receive a satisfactory offer, you can do the same thing with respect to signing the required documents.  This way, you will stay informed of the process, and your aunt will not be able to make important decisions (such as accepting an offer) without first consulting you and getting your signature.  When it is time to go to closing, either a lawyer or a title company will be hired to prepare the closing documents.  At that point, you can either attend the closing and sign the closing documents at the closing, or if you will not be attending the closing, the attorney or title company will prepare the appropriate Power of Attorney for you.  They can send the POA to you with instructions for the manner in which you should sign it, before a notary public, etc.; and then you can send the signed and notarized POA back to them in time for the closing.