i took lessons for maybe twow years when i was little and stopped for a long time. lately i started again and basically taught myself. it really helps to be able to read music easily, and know which notes are which keys on the piano.
it's easier if you start with pieces that don't have any sharps or flats.
you should also look into prelude and fugue no. 1 in c major from bach's "well tempered clavier" here's a link
http://www.free-scores.com/download-...ic.php?pdf=465. it's really good to practice sight reading