If I understand Liza correctly, digital negatives will be uncropped and unprocessed, basically what comes out of the camera will go onto the CD.
If you're sending your CD to family members to view on their computer screens, then I'd resize according to what size screen they have (windows picture viewer will downsize automatically to fill the screen in slideshow mode). In that case, I'd hedge my bets and resize to 1200px on the longest side.
If the CD is for the print shop, then don't resize the shots downward, let the print shop themselves sort that out, they'll generally do a great job.