CD to digital conversion

Ideally, the owner of the CD would copy the CD into their own Library as iTunes isn't designed for the purpose you intend.

That said (assuming that these are commercially produced CDs, not home burnt ones) once you have copied the CD into your iTunes Library:

1. you can go to Windows file manager (File Explorer) and copy the files for each song onto a memory stick (keep them in their respective folders. The folder structure will be something like iTunes Media / <Artist name> / <Album title> / <song name> or for compilation albums it's iTunes Media / Compilations / <Album title> / <song title>)
2. the CD's owner can copy from the memory stick onto their computer, putting the files into the iTunes Media folder as above.
3. it's then just a matter of using the iTunes menu option File/Add Folder to Library to get that music added to their iTunes Library

If the owner's computer has a CD drive, it may well be quicker and easier to copy the CDs using their computer and their iTunes. In my experience a capable CD drive can copy a CD in under two minutes (I don't have a CD to copy at this time so I can't be more accurate).

If the computer doesn't have a CD drive, do you have access to a portable CD drive that could be used? (It's probably not worth buying one just for this event.)