hey i knw one site....specially if you are frm india..its www.indianguitartabs.com though it has a lots of english tabs tooo...i got all frm their forum....i love this site...go try once......good luck!!
i get guitar tabs from: http://www.ultimate-guitar.com/
you may also want to download guitar pro and download tabs for guitar pro ;)
as for other musical instruments, i'm not sure where you can find one...sorry bud..