1) www.keylessonline.com : this website has very large collection of song notes for Tamil, Hindi, Telugu, Kannada and Malayalam language. They have both Indian and western notation for the songs. You can even request a song.
2) http://www.hitxp.com : this website has nice collection of song notes. They provide notes in classical indian notation system however if you want to convert it to western notation they provide keyboard mapping chart for this.
3) http://sari-gama.blogspot.com : sari-gama blog contain the piano notation of some of the best and popular songs. There you will learn how to find chords of the songs, mapping between western and carnatic notes.
4) http://www.song-notes.com : a very simple and resourceful website for casio/piano song notes. Song notes are available for Tamil as well as Hindi songs in both Western and Carnatic system.
