I've been playing piano for about 7 years. I taught myself when I began, so I've always been pretty self motivated, but I started taking lessons a couple years ago, and I've really improved by means of technique. But pretty much, I think the best way to learn is just by playing it a bunch. Hit your basics hard, such as reading the music, the scales and chords, and a little theory. You can photoread theory books, and photoreading the music would make you more familiar with the song itself, but the only way to learn to play it, is by actually playing it.
