Classicpianosolos.com
Free Classical Sheet Music in .pdf format with demonstrational videos
Learnjazzpiano.com
Though not very pretty, this site has a great collection of free jazz piano lessons and an active community. Of course, it's also free.
Zebrakeys.com
Free Piano Lessons with playback and diagrams
Musictheory.net
Practice you piano recognition skills with these exercises. Teachers can also customize the assignments and get students to send them results.
Free-online-piano-lessons.com
As you might guess, these are free online piano lessons
Plernpiano.com
Free interactive Piano Lessons
Berkleeshares.com
Free Lessons from Berklee College