For folks who are interested in making the switch from paper to digital sheet music systems, but are concerned about the time and effort it might take to manually scan large paper libraries, one solution may be to enlist the services of a document scanning service that can handle large volumes of scans very quickly.  One such service is Scandex Systems, located in Florence, AZ.  Scandex Systems specializes in being able to scan old books and delicate scores with their overhead scanning systems that don't require the binding to be cut or the book to be destroyed.  We recommend requesting scans in Black and White in either 150 or 300 dpi (dots per inch), and if possible, to have the borders removed for maximum screen real estate for music reading.  Completed scans can be downloaded as PDF files from their FTP site online, or delivered as CDs and/or DVDs.  Turnaround for most bulk scanning jobs can be as little as a day or two, depending on the volume and the type of scans required.
Visit http://www.scandexsystems.com/index.html for more information about their document and book scanning services.