A good piano teacher will hold particular personality traits and use specific teaching methods. Not only will you need to find a piano teacher that is used to teaching adults how to play, but you will also need to find a piano teacher that is a good piano teacher. Not everyone is. Before you hire a piano teacher to help you learn how to play the piano you should create a list of piano teachers in your area by searching in your phone book, looking up listings online, and more. Once you have a list made up of potential piano teachers, you should contact each one to schedule an interview to see if the two of you would be compatible. Simply by contacting each one you can probably narrow down your list. If a teacher does not respond to your request within a reasonable amount of time - cross them off your list. If a teacher does not want to offer you an interview before hiring them - cross them off your list.
If a teacher wants to charge you for the initial interview – cross them off your list. There, now you may have started with a very long list, but you just narrowed it down pretty quickly by looking at some of the piano teachers' personality and work traits that would not help anyone. Now you can move on to the interview where you can ask them all of the questions you have about learning the piano, their teaching methods, if they have worked with adults, how they work, where they each, and any other questions or concerns you may have.
Here are some particular signs to look for when seeking your piano teacher –
Motivation: They should have the ability to motivate you to want to learn how to play the piano, not bore you.
Professional: You want someone who has great work ethics, but is also friendly and easy to talk to.
Honesty: You need a piano teacher who is going to tell you when you are hitting the wrong keys, not just smile and nod. You may not be a musical person at all. A good teacher would tell you that in a professional manner if that is so.
Communication: Just like any other relationship your piano teacher needs to be able to communicate with you effectively. If you do not understand what your teacher is saying it will be much more difficult to learn.
Organizational: You need a piano teacher that can say "I would start you out with this lesson and move on through these lessons in my plan", not a teacher who would want you to figure out where you should begin.
But given all these qualities, the right piano teacher for you as an adult will also teach:
Music theory & harmony: To understand music, you really need to master theory and harmony.
Technique: Make sure the teacher includes a study of Hanon or some other technique book.
Sight reading: Most teachers teach this alone, so make sure you have the other areas covered as well.
Chords: Chords are a subset of harmony, but just make sure your teacher knows them and teaches them.
Arranging and improvisation: Make sure you're not "chained to the written score" -- learn to arrange songs and improvise too.
If they don't cover ALL these areas, cross them off your list and start again. It's just too important. When you find the right teacher you will know, and you will feel confident that you can learn effectively with that person. Doing the research ahead of time will definitely pay off in the long run.
If you already play the piano and know chords, then you'll want to get ahold of "How To Be a Musical Mindreader!". It shows how to know in advance which chords to use in a song before you ever play the song!