That depends on circumstances. Adobe Acrobat (not the reader) is probably the easiest way. Then put the file on the site and link to it. What happens when the user looks at it depends on the way the user has his browser set up - it'll show, download or ask him what he wants to do (you can't control that, it's up to the user).
If its static (ie if you are just want to store a bunch of PDF of sheet music) grab PrimoPDF is free, Then you just print your music to PDF. -------------------- Like my Answer? then please like My Post