You can print out some blank manuscript paper here:
Just click on the type you want and find 'print' on the menu bar of whatever program you are using to view the PDF image that appears. You can download them and 'save' them for future use. 

Single staff manuscript (voice only - for charts / lead sheets)
Piano (2 staves - treble and bass)
Piano-Vocal  (3 staves - voice, treble and bass)