Teach yourself how to play piano by using one of the many instructional books available in both bookstores and music stores. Generally, these books will start you off by teaching you how to read music, and how each note on the page corresponds to a specific key. After that, you will learn how to play the scales, chord progressions and then simple songs.
Use a videotape or DVD to teach yourself how to play the piano. Visual training tools such as these offer a distinct advantage over books, because they allow you to hear the music played properly, so that you can practice until you achieve the same results. Use online resources, such as Piano For All, to obtain books, videos and software to teach yourself how to play the piano (see Resources below). Many of these programs have money-back guarantees as well.
Learn how to play piano by ear if you are having problems with reading musical notation. Many books, tapes and videos can teach you how to play by ear by playing repetitive notes over and over until you are able to replicate the melody. While this will limit your ability to learn new songs as quickly as if you were proficient at musical notation, this may be an easier way for the casual player to learn.
Buy a learning keyboard that will help you to teach yourself how to play. These electronic instruments have keys that light up in a specific order, which will help you to learn songs faster. Many of these keyboards come with instructional books and videos as well, so that you can learn musical notation along the way.