Free Scores

http://www.cpdl.org/

http://www.imslp.org/

http://www.werner-icking-archive.org/

http://www.free-scores.com/

Anna Magdalena Notebook
Minuet in G
http://www.music-scores.com/skill/composer2.php?skill=3&name=Piano

http://people.ischool.berkeley.edu/~mkduggan/subject.html

http://www.e-partitions.fr/

Interesting score ideas
http://mander-organs.com/discussion/index.php