This website will get you the bare basics. And, btw, there is no such thing as piano sheet music. All music is written in the same sheet music style until about 1930.
try watching this guy,he goes over the notes and staff,and the theory, and he teaches it in a simple way(i think (*.*) but it can be a bit boring :*)
oops i forgot to put the link sorry (*_*)
Oh lol. I'm a newb. (;