I need a copy of the Sound of Music musical libretto (stage version) on line. I have the book from the company, but I need a larger version for the stage manager and director, and it doesn't copy well.

You can get it here:
link
And when you purchased the rights you should have been given a rental list which includes the full vocal scores and libretto for the cast.

Since I know you've purchased the rights...
here is the link to the rental eqipment from R&H.
link.