How do I learn how to read piano sheet music?

Easiest and cheapest way I've found is with some pretty sweet new software http://pianopract.us/. You can learn almost video game style without having to spend the money on a teacher. Curriculum is good and software is awesome. You'll just need to buy a MIDI keyboard and sign up.

I would suggest reading this article first http://ezinearticles.com/?Why-Does-it-Take-Most-People-So-Long-to-Learn-How-to-Read-Music?&id=2231209 But then as far as learning to read music the easy way, checkout http://www.SpeedyMusicReading.com

Im considering that you already know how to read and recognize music notes and the question you are asking is how to do it easily. What I do (and its worked for the past 9 years I've been playing piano from age 4 to 13) is I break the piece into sections (I'd start out small with something like 1-2 lines) and play those sections each as many times as you need to until you pretty much have it fluently (hands seperately of course) Do this with each hand... And then put your two hands together and play it slowly... (that is very important) and play those sections slowly as many times as you need the most important thing in this is patience and motivation... Dont give up!!! Good luck and most importantly.. have fun!!! :D

I suggest you go to this website: http://www.piano-lessons-info.com/read-piano-notes.html It teaches you how to read notes and play rhythms. It also has other neat stuff and it also shows chords too. Good luck!

A teacher? Or buy some "grade 1" (beginner) music books that teach you note names, then sheet music reading. Don't expect to learn it over night.