Here's a few of my favorite piano resources I have found over the years:
For tons of free piano things check out freepianostuff.com. It has everything from free sheet music, piano lessons, learning the piano keys, shopping for piano stuff, and more.
is the main place I went for my music books and sheet music (the actual
store is right down the street from me). They have tons of books,
sheet music, instruments, accessories and parts, piano teachers (if you
are in the Dayton, OH Area) and more.
has really cool, unique gifts for the aspiring piano player. They
have piano inspired designs for your kitchen, bathroom, your home in
general, even clothing and accessories.
If you want to learn how to play the piano or improve your beginning skills, I would highly recommend Learn & Master Piano.
This is an awesome set of DVD piano courses that you can do in the
comfort of your own home. Not to mention you would be saving
hundreds, even thousands compared to private piano lessons (which
average $120/month or $1,440/year).