Is there any self taught pianists?Watch
There a wee cheap app called Synthesia i've got on my pc, it's kind of like guitar hero for pianos, but actually accurate and you can feed it in basic midi files to follow (you find a MIDI of almost anything you'd ever want to play somewhere) ...with a USB piano keyboard I found it a fantastic tool to learn with myself.
I'm not self taught but it depends on how well/far do you want to take piano like learning to jus play songs, learning to be able to read notes or learning to know even the depth including theory etc. Pianist who can play by ear most likely has perfect pitch/ it's great help anyways. I'd say it's good to be patient with yourself and try to not develop bad habits etc