If you have a large amount of paper music to import, a good desktop scanner may give faster and better results, but you'll have to get the scans from the computer to the iPad. It works fairly well for me and I can just import the PDFs right into the library/page turning software.

To digitize my paper music, I took a chance on an iPad 'scanner' app that uses the iPad camera to take a picture of a page and then justify it and adjust the contrast to make neat PDF pages. I suggest making sure the software you select supports PDF because so much free music is in PDF (IMSLP) and it's a solid format you can use to import any existing paper music that you have. They might be prone to slide on hard floors or feel too spongy on deep carpet, so a small mat or pedalboard might be a good accessory. Also consider the surface(s) where you will use the page turner.

Regarding page turners, I suggest looking at reviews and/or talking to retailers and consider durability, battery systems, and ease of use, among other things. There is at least one company out there that makes both page turners and music library software, so you know their system will work fairly will with itself. I recommend looking at page turners first and then choosing from the compatible software packages.

Sheet music software that supports both page turners and PDF.

Besides the obvious iPad, you'll want three ingredients:

Use ipad as music keyboard for mac